- infirm (adj.)
[infirm 词源字典]
- late 14c., "weak, unsound" (of things), from Latin infirmus "weak, frail, feeble" (figuratively "superstitious, pusillanimous, inconstant"), from in- "not, opposite of" (see in- (1)) + firmus (see firm (adj.)). Of persons, "not strong, unhealthy," first recorded c. 1600. As a noun from 1711.[infirm etymology, infirm origin, 英语词源]