- not guarded; unprotected; undefended.
- open; frank; guileless: an unguarded manner.
- exposed to attack or capture by the opponent without recourse by the player, as a card, chess piece, etc.: an unguarded queen of clubs; an unguarded pawn.
- not cautious or discreet; careless: In an unguarded moment he had told her about his affair.
- without a safeguard, as a cover, barrier, or shield, for protection: an unguarded buzz saw.
- unprotected; vulnerable
- guileless; open; frank
- incautious or careless
adj.1590s, “not furnished with a guard,” from un- (1) “not” + guarded. Sense of “not on one’s guard, not taking heed” is attested from 1630s.