noun
backside
BAK-syd
noun
1
A person's buttocks.
"He slipped on the ice and landed hard on his backside."
2
The rear side of something, opposite its front.
"There's a loading dock on the backside of the building."
3
The reverse side of a printed page.
"The instructions continue on the backside of the sheet."
How to Use Backside
Learner’s notesIn plain EnglishThe back or rear part of something — often used informally to mean someone's bottom.
When to use it
As a word for buttocks, it's casual and mild — polite enough for everyday conversation but not formal writing.
Word Forms
backsides plural
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He slipped on the ice and landed hard on his _____.
Etymology
From back + side.