In SCA usage, Squires, Apprentices and Proteges are sometimes collectively referred to as dependents. This is probably to avoid using the term vassal since not all relationships between a Peer and his/her dependents involves fealty.
With the creation of the Order of Defence the situation becomes more complicated. With various Kingdoms already having established fencing traditions it seems unlikely that there will be an SCA-wide term for the dependents of Masters of Defence. For example, the East Kingdom appears to be settling on provost, while in Drachenwald that term is already in use by the Academy of Defence. Drachenwald may use scholar, but that term also seems unlikely to have universal appeal.
The question of what to call someone who is a dependent of a double peer, a triple peer, or a quadruple peeer sometimes arises. Some choose a single term from one of the above, expressing a focus on a given area. Some choose a portmanteau name such as apprentegé for an apprentice/protegé combination. Alexandre d'Avigne refers to his dependents as either 'apprentegé' or 'apprentegét' depending on whether or not they fence and cadet needs to be worked in. More generally, they were sometimes pandiscipula or 'universal students,' a term which gained some traction in the East Kingdom, often in its shortened form of 'panda.'
The term 'stoplight' is sometimes used, at least in Drachenwald to refer to someone who is the dependent of a Knight, Laurel, and Pelican, since the three nominal colours of their belts would be red, yellow, and green - the same as are used in traffic signals in many places.
See also S.A.P