1.
defenseless; unguarded; unprotected
Lacking defense or protection against attack, danger, or harm.
無防備な状態だ。
It's a defenseless state.
無防備な都市を攻撃するのは国際法違反だ。
Attacking an undefended city violates international law.
サイバー攻撃に対して無防備な企業が多い。
Many companies are unprotected against cyberattacks.
2.
unguarded; careless; open
Showing no caution or wariness, often in a personal or emotional sense. Can describe someone who is innocently open or naive.
彼女の無防備な笑顔。
Her unguarded smile.
寝顔は無防備で可愛い。
Their sleeping face is unguarded and cute.
彼は人を疑わない無防備な性格で、よくだまされる。
He has an unguarded personality that doesn't suspect others, so he often gets deceived.
Composed of 無 (without) + 防備 (defense, guard). Can describe physical defenselessness (a city without military protection) or personal openness (an unguarded expression). The figurative sense is common in everyday conversation and manga/anime descriptions.
COMMON COLLOCATIONS:
- 無防備な姿: an unguarded appearance
- 無防備な都市: an undefended city (legal/military term)
- 無防備に{さらす}: to leave exposed without protection
SIMILAR WORDS:
- 油断: carelessness; letting one's guard down — focuses on a momentary lapse in vigilance
- 丸腰: unarmed — specifically without weapons
- 無力: powerless — lacking strength or ability rather than defense