interjection
frightening; terrifying; scary
Exclamation used when something is scary or frightening, often in casual speech.
こわ！あの犬、すごく大きいね。
Scary! That dog is really big, isn't it?
こわ！急に電気が消えた。
That's terrifying! The lights suddenly went out.
Adjective meaning 'scary' or 'frightening'; こわ is the interjection form, used as an exclamation.
Derived from the adjective 怖い (こわい, 'scary'), shortened to an interjection.