na-adjective, noun
unprepared; off guard
Describes being without preparation or readiness, often in a situation where one is caught off guard.
敵は不用意なところを突かれた。
The enemy was struck while off guard.
不用意なまま本番に臨むのは危険だ。
It is risky to go into the real thing unprepared.
na-adjective, noun
careless; imprudent; indiscreet; inadvertent
Used for actions, remarks, or handling of things done without enough caution or forethought; common in 不用意な発言 and 不用意に.
彼の不用意な発言が大きな問題になった。
His careless remark became a major problem.
不用意に個人情報を書き込まないでください。
Please do not enter personal information carelessly.