1 〈物事が〉危険を伴う, 危険な, 危ない.

・a dangerous road, voyage, etc.

・dangerous driving 危険な運転.

・a dangerous drug 危険薬物, (特に)麻薬.

・The river is dangerous to swim in.＝That's a dangerous river to swim in.＝It's dangerous to swim in that river. あの川は泳ぐには危険だ.

2 〈人・動物など〉(危)害を加える恐れのある, 危険な, 物騒な.

・a dangerous dog [man].

・a dangerous object [thing] 【法律】 危険物.

・Such men are dangerous. あんな[そんな]人間は危険だ (Shak., Caesar 1. 2. 194).

3 《古・方言》 〈病気が〉(危険なほど)重い, 〈人が〉危篤の, 重態の.

・a dangerous illness.

〜・ness n.