怖い
こわい · kowai · JLPT N4 · i-adj
scary
👻 kowai sounds like cower-y: scary things make you cower
Say kowai aloud and it is close to cower-y. Scary things make you cower, so the sound itself carries the meaning. It also differs from kawaii (cute) by one vowel: ko = cower, ka = cute.