backside

Everyday

1. (informal) The part of the body you sit on; your bottom. tree →
2. The back part of something (rare): the backside of the building. tree →
3. (informal, phrases) Get off your backside: stop being lazy and do something. tree →

In the lessons

A jokey, slightly rude everyday word, softer than many other words for the bottom; in stories it is used for comic falls or telling someone off. In maths and science lessons say "back" or "rear" instead. Phrases: fall on your backside, sit on your backside, a pain in the backside (an annoying person or thing, rude).

Examples

• He slipped on the ice and landed on his backside. tree →
• (informal) Get off your backside and tidy your room! tree →
• The donkey kicked the farmer in the backside. tree →
• (informal) Doing all this homework is a pain in the backside. tree →
• My backside hurt after the long bike ride. tree →
• The mud left a brown patch on her backside. tree →

Note

Informal and a bit cheeky; polite words are bottom or behind, and "rear" for a vehicle. "Pain in the backside" is mildly rude. Do not use it in formal writing.