야속해요 · 야속했어요 · 야속한 (+noun)
to be hurtfully cold, unkind (making you feel let down)
Example
생일을 잊어버린 친구가 조금 야속했어요.
I felt a little hurt that my friend forgot my birthday.
Word parts
Hanja mean 'rustic, vulgar'; today it means feeling hurt by someone's coldness.
Good to know
Pronounced [야소카다]; also for things like 야속한 세월 — time that cruelly flies.