- understudy (v.)
[understudy 词源字典]
- also under-study, 1852, in the theatrical sense "memorize a part so as to be capable of performing on short notice it in the absence of the one to which it is assigned," from under + study (v.). The noun is attested from 1848, translating Italian supplimento.[understudy etymology, understudy origin, 英语词源]