- flat-footed (adj.)
[flat-footed 词源字典]
- c. 1600, "with flat feet;" see flat (adj.) + foot (n.). Meaning "unprepared" is from 1912, U.S. baseball slang, on notion of "not on one's toes;" earlier in U.S. colloquial adverbial use it meant "straightforwardly, downright, resolute" (1828), from notion of "standing firmly."[flat-footed etymology, flat-footed origin, 英语词源]