fill-in

Synonyms:

backup, backup man, relief, reliever, stand-in, substitute

Types:

locum, locum tenens

someone (physician or clergyman) who substitutes temporarily for another member of the same profession

double, stunt man, stunt woman

a stand-in for movie stars to perform dangerous stunts

alternate, replacement, surrogate

someone who takes the place of another person

Type of:

compeer, equal, match, peer

a person who is of equal standing with another in a group