Underbum
noun, slang ·Uncommon ·College level
Definitions
- 1 The lower part of the buttocks, as revealed by certain clothing such as skimpy shorts. UK, slang
"Now, no one is pretending this is an easy look to pull off, but whereas the whale tail was shaming because it was a fail – the byproduct of you scrabbling in the bottom of your bag for your Oyster card – the underbum is at least bold and brazen, in a lollipoppy, Katy Perry or Rihanna kind of a way."
Synonyms
All synonymsExample
More examples"Now, no one is pretending this is an easy look to pull off, but whereas the whale tail was shaming because it was a fail – the byproduct of you scrabbling in the bottom of your bag for your Oyster card – the underbum is at least bold and brazen, in a lollipoppy, Katy Perry or Rihanna kind of a way."
Etymology
From under- + bum, by analogy with underboob.
More for "underbum"
Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.