a/ The back or false edge of the blade b/ To move backward. e.g. to step back.
BCU
(Film) Big close up. 
Back lighting
Lighting from behind the subject in order to achieve for example, a silhouette. 
Back pedal
To move backward while still facing your opponent.
Backsword
An eighteenth century weapon similar in style to the Scottish Claymore. Sword with straight one edged blade.
Backswording
a/ Practice of the backsword b/ Cutting attacks made from the elbow or wrist, made with the false or back edge of the blade.
Backward lunge
An evasive action which removes the body backwards out of opponents the attack, while still facing the opponent.
Backward spring
A leap backwards, out of distance, from the lunge.
BADC
The British Academy Of Dramatic Combat. London based fight organisation.
BAF
British Academy of Fencing. A professional body which governs coches of the sport of fencing.
BAFD
Former name for the BADC and BASSC before they split due to politics and wrangling. A sort of feud exists to this day. At least that's how it appears to the outside eye.
Balance
The state in which a combatant keeps weight distribution divided equally between his feet.
Baldric
A belt or girdle, usually of leather, that supports the weight of the wearers sword across his/ her chest.
Balestra
Italian term for a compound piece of footwork which rapidly closes the distance between opponents, usually, but not always followed by a lunge. A form of preparation. a short jump forward during an attack.
Ballock Dagger
14 -17century dagger with two lobes at base of grip. Phallus like.
Barrage
Play off bout or bouts between tied fencers for promotion to a higher round in a tournament or to determine first place in a final round. The tie would be in the number of bouts won and lost in the round. A TIE.
Basket Hilt
Popular cavalry sword, still in ceremonial use today. The basket shaped hilt of the weapon envelopes the hand offering some protection. a hilt enclosing the hand constructed of bars and broad plates.
Bassa
Low line.
Basso
Literally "low" or "lowered". Used in reference to the lowest  immediate target on the opponents body. The knee or foot.
Bastard Sword
Also known as a hand and a half. A sword which can be used with one or both hands.
Battement 
(See beat.)
Battre de main
To parry with the hand.
Beat
a/ A sharp striking movement made on the opponents blade, causing a deflection or obtaining a reaction from it - a preparation. b/ Theatrical term applied to key sequences within a play or an within an actor's performance. A play or performance can be broken down into these key "beats", each advancing the story or a character's development.
Beat disarm
A beat on the opponents blade which results in a disarm.
Beat Parry
A parry that punches the opponents blade sharply off line.
Besnard, Charles
Seventeenth century master of the "Academie Royale d'Arms. Introduced the salute proceeding a bout.
Bind
A method of removing the offending blade by taking the opponents foible (pris d'fer) from a high to a low line and vice versa, diagonally across the line of engagement.
Bind away
A bind which throws the opposing blade off line with force.
Bind over
A bind which carries the blade up and over, then down the opposite side. Used to disarm or pin opponents weapon.
Blade
The part of a cut and thrust weapon with which main attacks are made. The tip, foible (feeble), middle,  and forte.
Black box
Theatre which is an empty space, to be filled in any configuration of audience and stage area.
Block
a/ Defensive action designed to stop opponents attack by placing a barrier in it's path. e.g. with your own blade or with a shield or even arm. b/ The process of laying out the action in a fight or within a play. Known as blocking.
Blood bag
A small bag filled with fake "blood", which an actor bursts when struck by a weapon. Unreliable messy little things which drive wardrobe crazy. 
Blueing
The surface colouring of steel by machine or chemical means.
Boar's thrust
A violent thrust punched into the body of an opponent after the sword hand is suddenly dropped to the level of the knee.
Boat Shell Hilt
A sword with a heart shaped hilt in front of the hand.
Bodkin
Skewer-like piece of cutlery used in skinning and preparing of game.
Body blow
An armed or unarmed attack on the body intended to hit or appear to hit.
Body Double
(Film) An actor or stuntman that replaces the actual actor for difficult or dangerous moments, or in times when the actual actor is only partially in shot.
Book
1/ Another term for the script. 2/ The DSM's script which has all moves, cues, changes etc. marked in it.
Botta
An attack from it's beginning to completion. A blow or thrust.
Botta Dritta
A pronated thrust from the right. The straight thrust.
Botta in tempo
Attack while the adversary is preoccupied with a parry, bind or feint.
Botta Lunga
Grand lunge. Classical movement which replaced passing in the seventeenth century.
Botta Secreta
A fabled "mystery" attack or hidden technique.
Bout
A sequence of activity between two fencers.An assault between two fencers in which hits are scored.
Break
A pause between sections in theatrical swordplay. 
Breakaway
Props or set pieces with sections designed to come away.
Breaking ground
Rendering ground to your opponent due to foot movements. retiring by stepping backwards.
Bridge
A move which links two actions in theatrical combat. This may be a step for balance, or a blade movement, preparation etc. A "bridging" move.
Broadsword
A term which applies to almost all swords of the medieval period. Reasonably heavy weapon almost always with cross guard quillions. A sword with a broad two edged blade.
Brochiero
Variety of Buckler.
Broken time
When two movements in a sequence are deliberately configured not to follow immediately  after one another, in order to gain an advantage on one's opponent.
Buckler
Small usually round shield generally used in the middle ages and early renaissance. Sometimes called a target. Often fitted with a central boss or spike.
Burgonet
16th - 17th century light open faced helmet with peak and cheek pieces.
Button
Round metal or plastic bulb used to blunt the tip of blades for practice.
Byknife
Knife fitted in the sheath of a dirk.