n. 25B6; noun STAND-IN, substitute, replacement, reserve, fill-in, locum, proxy, back-up, relief, standby, stopgap, second, ancillary; informal sub; N. Amer. informal pinch-hitter.
UNDERSTUDY
Meaning of UNDERSTUDY in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012