Bumming
The Century Dictionary and Cyclopedia
noun.
In
mining
: The heaving or rising of the floor.
noun.
The emitting of a hollow sound when struck.
Wiktionary, Creative Commons Attribution/Share-Alike License
verb.
Present participle of
bum
.
Word Usage
"And many of our listeners have told us, they're kind of bumming out, too."
verb-stem
bum