괜히

Adverb

1. 1

   vainly; in vain; to no avail

   Without substance or particular reason.

   Korean definition: 특별한 이유나 실속이 없게.

   • 친구는 술에 취하면 괜히 심술을 부린다.

     When my friend gets drunk, he gets nasty for no reason.

   • 이럴 줄 알았으면 안 오는 건데 괜히 왔어요.

     If I'd known it would be like this, I wouldn't have come. I came for nothing.