stand–in 
/ˈstændˌɪn/ noun
plural stand–ins /ˈstændˌɪn/ noun [count] : a person or thing that takes the place of someone or something else for a period of time
▪ He was the boss's stand-in during her illness. — see also stand in at 1stand
▪ He was the boss's stand-in during her illness. — see also stand in at 1stand
