na-adjective, adverb taking the 'to' particle, noun or participle which takes 'suru'
completely exhausted; limp; weak
Describes a state of extreme physical or mental exhaustion, often with a sense of limpness or lack of strength. Can also describe objects that are flimsy or weak.
一日中歩いて、もうヘロヘロだ。
I've been walking all day and I'm completely exhausted.
この段ボールはヘロヘロで、すぐに潰れそうだ。
This cardboard box is so flimsy it looks like it'll collapse any moment.