Causing fear or dread; terrifying or frightening—used to describe something that inspires terror or horror.
その映画は映像がリアルで本当に恐ろしかった。
That movie's images were realistic and truly terrifying.
あの事故のニュースは恐ろしい結果を示していた。
The news about that accident showed terrifying consequences.
夜道を一人で歩くのは恐ろしいと感じる人もいる。
Some people feel frightened walking alone on a road at night.
Used to express astonishment or an extraordinary degree; often used as the adverb 恐ろしく to mean 'amazingly' or 'tremendously'.
彼の説明は恐ろしく分かりやすかった。
His explanation was amazingly easy to understand.
その山は恐ろしく高くて、登るのは大変だ。
That mountain is tremendously high and climbing it is hard.
恐ろしく静かな夜で、町全体が眠っているようだった。
It was an eerily quiet night; the whole town seemed asleep.