AMERICANA: also known as American armbar, bent armlock, figure-four, figure-4, hammerlock, paint brush, top wrist lock, ude garami, keylock, lateral keylock, v-lock, and chave de braço (Portuguese). A submission in which you grasp your opponent's wrist with one hand, then bring your other arm underneath theirs, grabbing your own wrist  With the opponent's elbow pointing downwards, you then use your grip to simultaneously push their wrist back and lift their elbow up.

The name 'Americana' comes from a trip Bob Anderson made to Brazil in 1978, during which he trained (initially by accident, as he was supposed to be meeting with the Brazilian Wrestling Federation, not a jiu-jitsu school) with the legendary Rolls Gracie. According to Anderson, "I didn't come down there and go 'ok, I'm going to show you the Americana armbar and I'm the guy that invented it', it just grew out of what I knew and what he [Rolls] liked...he later - I didn't even know - he called it the Americana because I was the American wrestler that came down and showed him the move and that's how the Americana armbar got started."

ARMBAR: also known as armlock, juji gatame, armeloque (Portuguese) . A lock in which the elbow joint is hyperextended.

BASE: generally refers to balance (e.g., someone who is difficult to sweep may be described as having a "good base"), in particular the position the person on top takes when in someone else's guard: keep your weight low, back straight, head up, knees wide.

BELT: In BJJ, there are five belts (faixa) - white (branca), blue (azul), purple (roxa), brown (marrom) and black (preta). On average, to go from white to black will take 10 years, but this varies: there are also famous exceptions, like BJ Penn. The way to get promoted at most schools is through the instructor observing your performance in class and in competitions, giving you your next belt when they feel you've proved your ability on the mat. Some instructors, like Roy Harris, have a more formalized system, but this is rare. Stripes on a belt are also common, which can sometimes merely be a measure of how long you've been training, while at other clubs they are added in the same meritocratic fashion mentioned above.

BREAK FALL: a method by which you can reduce the impact of being thrown or falling. The general principle is to disperse the force by slapping the ground with your hand (specifically the palm heel). Differs slightly depending on direction - for example, with a backwards break-fall, both hands slap the ground, whereas with a side break-fall, you only use one hand.

Bridge: see

BUTTERFLY GUARD: a type of OPEN GUARD, in which your upper body is raised with your feet inside their legs

CLINCH: A position in which one person has gripped the other whilst standing, such as UNDER HOOKING their arms. In BJJ, this will generally be the precursor to a TAKEDOWN. Also seen in many other martial arts, especially Muay Thai, which uses the same position as an opportunity to throw knees into the opponent's legs and body.

CLOSED GUARD: a position in which one person is on their back and has their legs wrapped round the other, feet hooked together using the ankles and instep.

DE LA RIVA GUARD: this is a type of OPEN GUARD in which your leg goes around the outside of their same side leg, hooking on the top of their other leg with your instep. It is named after Ricardo De La Riva, a Carlson Gracie black belt who is best known for the position.

DOUBLE LEG: also known as morote gari (judo) and baiana (Portuguese). A takedown executed by attacking both legs, generally gripping the back of the knees to facilitate bringing your opponent to the floor.

FIGURE-FOUR: also written as figure-4. When used on an arm, also known as a double wrist lock. A hold in which the positioning of the limbs resembles the number '4'. For example, used in the AMERICANA and the KIMURA.

FLOWER SWEEP: also known as pendulum sweep and see-saw sweep.

GABLE GRIP: a grip in which your palms are together, fingers wrapped round the edge, not using the thumbs. As far as I'm aware, its named after legendary wrestler Dan Gable, but I don't have any further information on that - feel free to put up a comment if you know anything about the origins.

GI: also known as kimono and quimono (Portuguese). This is the uniform practitioners of Brazilian jiu jitsu wear, made of heavy woven cotton. It is similar to the uniform worn in judo, though there are some slight differences in a specifically BJJ gi: e.g., the 'skirt' of the jacket tends to be shorter than a judo gi.

GUARD: also known as do-osae. A position where one person in underneath another, but maintains a neutral position through the use of their legs (as opposed to MOUNT or SIDE CONTROL, where the person on top is dominant). The basic position is CLOSED GUARD, but can also be OPEN, each of which have numerous variations.

GUILLOTINE CHOKE: may see this referred to as guilhotina (Portuguese), mae hadakajime and front headlock. Applied by wrapping one arm under the neck, gripping your own bicep of the other hand, securing that behind the head, then squeezing for the submission.

HALF-GUARD: also known as meia guarda (Portuguese) and ashigarami. Similar to GUARD, except that in this case, only one leg has been trapped as opposed to the waist or both legs.

HOOKS: also known as gancho (Portuguese). Normally refers to getting your feet wrapped under a limb, especially under the leg. For example, for butterfly guard, you need to 'hook' your feet to secure the position. This is also important when TAKING THE BACK, to stop your opponent REVERSING you.

KIMURA: might see this referred to as bent armlock, chicken wing, reverse figure-four, hammer lock, ude garami, entangled armlock or keylock. Reverse of the AMERICANA, named after Masahiko Kimura who famously used it to defeat Helio Gracie.

MOUNT: also known as tate shiho gatame. Position where one person is sat on top of the other, legs straddling the torso.

OMOPLATA: might see this referred to as sankaku garami or shoulder lock. A submission which uses the legs against an arm in order to attack the shoulder. Hence the name: omoplata means 'shoulder blade' in Portuguese.

OPEN GUARD: also known as choza, I think. This is a GUARD position in which the legs are not wrapped around the waist with the ankles crossed (as in CLOSED GUARD), but instead may be between your opponents legs, on their biceps, across their stomach etc. Hence 'open' rather than 'closed', because the legs are not locked together, remaining mobile.

OVERHOOK: also known as a whizzer (from wrestling). A position in which you have managed to get a limb secured over the top of your opponent's arm or leg - i.e., 'hooked'.

PASSING THE GUARD: also known as passando a guarda (Portuguese) and hairigata. The process by which the person 'in the guard' (between the other person's legs) gets their legs past, commonly moving into SIDE CONTROL or MOUNT.

POST: used as a verb, posting. A term which refers to placing a part of your body on your opponent or the mat in order to gain stability and prevent or set up movement. For example, if someone is attempt to use the UPA to escape your MOUNT, you can 'post' your arms to the relevant side in order to prevent being swept.

POSTURE: also known as postura (Portuguese). Good posture means that your back and neck are straight, your head in line with your spine.

PUSH SWEEP: Similar principle to a SCISSOR SWEEP, except that you push on the top of the knee rather than chopping with your leg and don't necessarily have a shin against the stomach. 

REAR NAKED CHOKE: also known as hadaka jime, sleeper hold, mata leo or mata leão ('to kill the lion' in Portuguese), often abbreviated to RNC. Same principle as the GUILLOTINE, but from behind the opponent as opposed to a front headlock position.

REVERSAL: also known as inversão (Portuguese), and can be a verb - reverse. A term used to describe a movement or technique that manages to change the combatants position. For example, if you managed to SWEEP an opponent who previously had MOUNT, meaning that you ended up in their GUARD, this could be described as a reversal.

ROLLING: a term often used in BJJ and other grappling styles, which has the same meaning as 'sparring' or randori - in Portuguese, the noun is either dar um rola or escrima. Generally when rolling, one person attempts to submit the other, who fully resists them. Alternately, the instructor may use 'specific sparring' in order to familiarize students with certain positions, such as sparring from guard with the end goal of passing or sweeping.

SCARF HOLD: also known as kesa gatame (judo), head and arm (wrestling). This is a controlling position in which you are facing towards your opponent's head, with one arm threaded under their armpit and around their neck, while your other hand is pulling their remaining arm tight into your stomach.

SCISSOR SWEEP: also known as hasamigaeshi or possibly kanibasami. A sweep partly accomplished by applying force with a leg on either side of your opponent, hence the 'scissor' description.

SHRIMPING: also known as snaking, snake move, hip escape, hipscape and ebi. Used to describe a motion in which you use your legs to shift your hips to one side or the other, pushing out your posterior. This is an integral part of BJJ, especially escapes.

SIDE CONTROL: also known as side mount, cross-side, across side, thousand kilos, one hundred kilos, 100 kilos, cem kilos (Portuguese) and yoko shiho gatame. A position in which you are on top and perpendicular to your opponent.

SIT-UP SWEEP: also known as chest to chest, hip bump and hip heist. A sweep from the guard where you open your legs, sit up (pushing off an arm), isolate an arm by the elbow, raise your hips, then swivel in place to end up in mount.

SLIDING CHOKE: A choke in which one forearm is pressed against the neck gripping a collar, while the other pulls down on the remaining lapel, the additional leverage of which results in the choke.

STACK: can be a verb - stacking. A position in which you compress your opponent by squeezing their legs towards their head or chest. Ideally, their knees will be pressing against their head. This is often used when passing the guard, or when escaping submissions such as ARMBARs.

SUBMISSION: sometimes abbreviated to sub. The term used to refer to any kind of finishing hold which results in one person TAPPING.

SWEEP: also known as raspagem (Portuguese). Numerous techniques in BJJ which enable the person on the bottom to REVERSE their opponent and end up on top - e.g., SCISSOR SWEEP.

TAKEDOWN: also known as queda (Portuguese). As the name would suggest, this term is used to refer to any technique which takes the opponent down to the ground. For example, a throw or a trip.

TAKE THE BACK: also known as taking the back and pega as costas (Portuguese). When somebody manage to secure a position on the back of their opponent, aiming to get their legs wrapped around the hips, with feet acting as HOOKS - can be referred to as back mount and rear mount.

TAPPING: when someone indicates they wish to concede by slapping the ground with their hand, normally due to the pain caused by a particular SUBMISSION, or occasionally simply out of exhaustion. Sometimes they will tap on their opponent’s body instead, or even with their feet if both arms are trapped – this is uncommon, however, and potentially dangerous if the opponent can’t hear you (their head may well be nowhere near your feet). An agonised yell tends to work too. ;)

TRIANGLE CHOKE: also known as triângulo (Portuguese) or sankaku jime (or possibly sangaku jime). A choke in which you use your legs to squeeze your opponent's own arm against their throat. The name comes from the position of the legs, with one across the back of the person's head, the other securing the hold by locking a shin underneath a knee.

TURTLE: can be a verb - turtling. A position in which you are on all fours, with your posterior pressed to your ankles, limbs tightly tucked into your body.

UNDER HOOK: opposite of the OVER HOOK. A position in which you have managed to secure a limb underneath one of your opponent's, such as under their arms when in the CLINCH.

UPA: might also hear this referred to as bucking, bridging, bumping, barrigada (Portuguese) etc. Raising the hips when on your back, normally in an attempt to make space from under mount, but can also be used as part of other escapes.

X-GUARD: a position in which you have your same side hand gripping over the top of their knee, while one of your legs hooks behind their other knee, while your other foot is up by their hip. There is a book about the position, The x-Guard, by Marcelo Garcia.