besieging - process of closing in from out of measure while using some siege technique. This is considered to be first phase of every attack, and it is an analogy of army besieging a castle.
bind - situation when my and the opponent's sword are in contact, so that my sword can influence what the opponent's sword is doing and vice versa. Only contact of two blades is considered to be a bind; not a contact of blade and the shield. I.33 defines 4 types of bind based on geometry of the blade - binding above and on the left, above and on the right, below and on the left, and below and on the right.
binder - when fencers are in the bind, binder is the one who has the initiative. He can decide what will happen.
custodia (guard, ward) - a position ("where are my weapons at one point in time"), that is not intended as a defence (it doesn't close any line of attack with a sword). Custodiae are intended to be used in first phase of attack (out of measure or while closing in). When fencer sucessfully closes the distance, he should then be using only a subset of custodiae, longpoints.
entering - When I succesfully besiege my opponent, I then fight in close distance (usually in the bind) for a chance to get my sword behind the defence of my opponent. If I succeed, I can then hit him, because nothing is preventing me from it. The act of getting the sword behind the opponent's defence is called entering (or invading). It is an analogy of invading army entering the castle walls.
halpschilt - an obsessio; a simple downwards cut. It can be either push cut or draw cut, but it always has to pass on the right side of the shield.
invading - probably synonymum to entering.
krucke - an obsessio; a rising cut launched from under the shield arm.
longpoint family - A set of three custodiae (longpoint, high longpoint and priest's special longpoint), that are intended mostly to be used in second phase of attack, because of their ability to work in the bind. In I.33, longpoint is defined by its ability in binding, NOT by its ability to threaten the opponent with a tip of the sword.
mutatio gladii - an action of switching from below position to above position in the bind, and a way how to do it safely. It is an action intended to be used in the second phase of combat, and a correct solution of bind below and on the left.
nucken - a false-edge cut aimed to the head, used from a contact distance.
obsessio (siege) - a technique used in order to safely close the distance from out of measure. Typically (but not only) such technique is a cut or thrust that threatens the opponent. Obsessio by itself can be dangerous for the opponent, but it is viewed mostly as a vehicle that safely gets me to contact distance and a bind. Some custodiae can keep me safe while closing in by themselves (eg. langort/longpoint), so they are in I.33 also sometimes used as obsessiones.
omitting the bind - a situation when the opponent blocks you siege with the shield, but does not include sword in the defense. This is a situation explored by multiple plays of I.33.
opposition (contrarium) - a general term with a broad meaning. Contrarium is anything, that one fencer does against what the other fencer does. For example a schutzen can be used as a contrarium against the attack of the opponent. But an attack can also be considered a contrarium to the opponent taking a position (eg. halpschilt can be used as a contrarium to the opponent taking prima custodia).
rebind (religatio) - an action of taking the bind (if I wasn't there before) and pushing the opponent's blade down, done in a sweeping motion. Rebind is a general technique for regaining control in overly chaotic situation. Also useful for gaining advantageus position in the bind.
separation of sword and shield (separatio/dividendo scuti et gladii) - concept of cutting or thrusting between the sword and shield of the opponent. If sucessfully performed, it is very hard to be stopped, because the action needed is unintuitive.
seven basic guards - subset of custodiae; 7 positions that (as I.33 says) all the fencers use. All of them are either starting or ending points of basic cuts and thrusts. All simple cuts and thrusts are alwayes switching from one custodia to another custodia.
schiltslack - an action of hitting the opponent with the shield; typically used not to harm, but to control the opponent. Schiltslack is an action intended to be used in second phase of combat, and a correct solution of bind above and on the right.
schutzen - a parry action/position. Schutzen is a crossover between a position that statically closes one line of attack with the sword, and an action (a cut) that gets my sword into that position. It is defined mostly by the idea of blocking the opponent's attack.
stichslack - an action of hitting the opponent or his weapon with the shield while thrusting him with sword arm going below the shield arm. Stichslack is an action intended to be used in the second phase of combat, and a correct solution of bind below and on the right.
strike (plaga) - a general term for a cut or thrust aimed at the opponent's body from contact distance. Plaga is an attempt to deliver killing-blow. So cut to stop the opponent's sword is not plaga (it is schutzen). A cut performed while closing in from out of distance is not plaga (it is obsessio).
the bound - when fencers are in the bind, the bound is the one who doesn't have the initiative. He can only react to what the binder is doing.