- free-wheeling (adj.)
[free-wheeling 词源字典]
- also freewheeling, 1903, from free wheel (1899, see free (adj.) + wheel (n.)); a bicycle wheel that turns even when not being pedaled, later from the name of a kind of automobile drive system that allowed cars to coast without being slowed by the engine. Figurative sense is from 1911.[free-wheeling etymology, free-wheeling origin, 英语词源]