1. What does it mean?
웃프다 blends the ideas of 웃기다, being funny, and 슬프다, being sad. It describes humor mixed with disappointment, sympathy, or an uncomfortable recognition of your own situation.
Also written or said as 웃픈, utpeuda
2. The nuance
The sadness can be mild and self-deprecating rather than tragic. Use care with somebody else's serious misfortune: finding a situation 웃프다 does not mean the person wants it treated as a joke.
3. Examples
“쉬려고 휴가 냈는데 밀린 집안일만 하다 끝나서 웃프다.”
I took time off to rest, but spent it catching up on chores. It's funny in a sad way.
“취업 준비하는 친구 만화가 너무 내 얘기라 웃펐어.”
My friend's comic about job hunting was so much like my own life that I had to laugh, sadly.
Sources
KoreanClass101: Korean language lessons
References support the meaning and usage. Example sentences are written for NoCapWiki.