bum out
Upper Intermediate (B2)informal
To make someone feel really sad or disappointed.
"Hearing that the concert was cancelled really bummed me out."
Hear it in context

Can a Pro Golfer Help Me Win a Match?!
Cole Anderson-James · 11:23
Bum out.

HULA POKEY | Hawaiian Hokey Pokey | ELF Learning
ELF Kids Videos · 1:40
Put your bum in, put your bum out,

Q&A Special | Shut Up I'm Talking Podcast EP. 86
Shut Up I'm Talking · 4:55
I've never had my bum out in public.

Q&A Special | Shut Up I'm Talking Podcast EP. 86
Shut Up I'm Talking · 4:51
they walk around with their bum out in little Yeah.

Ben Stiller, Adam Scott & Britt Lower Talk ‘Severance’ | The Jonathan Ross Show
The Jonathan Ross Show · 4:15
Always with my bum out on the photocopier, you see.