- off-hand (adv.)
[off-hand 词源字典]
- also offhand, 1690s, "at once, straightway," from off (adv.) + hand (n.). Probably originally in reference to shooting without a rest or support. Hence, of speech or action, "unpremeditated" (1719). Related: Off-handed; off-handedly.[off-hand etymology, off-hand origin, 英语词源]