continuity girl:
(also ‘continuity person‘ or ‘script supervisor‘; plural: ‘continuity girls‘; pronunciation: the letter ‘c’ is said with a ‘k’ sound as in “kong”; male: ‘continuity man’)
a woman (or man) whose job is to see that an actor’s make-up, clothes, etc. are consistent, i.e. all the things (set properties), make-up, clothes, etc., the same as in the previous shot of the same scene in a film making, especially when the scene is a long one or shot from different angles on different days,

a continuity girl (L) checking the ropes on an actor
It is the job of the continuity girl to see to that an actor sipping tea from a cup and has drunk half of it in one shot, has only half a cupful of tea, not a full cup, in the next shot of the same scene.
Suppose an actor in a scene is talking to another for a long time while smoking a cigarette, it is the continuity girl/person’s or script supervisor’s job to see to that the cigarette gets shorter and shorter as the time passes, in shot after shot from different angles of the same scene.

a radio station continuity announcer
