fill-in

(noun) someone who takes the place of another (as when things get dangerous or difficult). Synonyms: stand-in, substitute, relief, reliever, backup, backup man. Examples: "The star had a stand-in for dangerous scenes." "We need extra employees for summer fill-ins."

(verb) supply with information on a specific topic. Synonyms: fill in. Example: "He filled me in on the latest developments."

(verb) represent the effect of shade or shadow on. Synonyms: shade, fill in.

(verb) be a substitute. Synonyms: substitute, sub, stand in, fill in. Examples: "The young teacher had to substitute for the sick colleague." "The skim milk substitutes for cream--we are on a strict diet."

(verb) write all the required information onto a form. Synonyms: complete, fill out, fill in, make out. Examples: "Fill out this questionnaire, please!." "Make out a form."