실망스러워요 · 실망스러웠어요 · 실망스러운 (+noun) (ㅂ irregular)
disappointing
Example
기대했던 영화가 생각보다 너무 실망스러웠어요.
The movie I had been looking forward to was much more disappointing than I expected.
Word parts
실 lose+망 hope
Literally 'lose hope' plus -스럽다 'seeming, giving that feeling'.
Good to know
실망스럽다 describes the thing; for the person, use 실망하다: 저는 실망했어요.