Word
buns
臀部（俚语）
the fleshy part of the human body that you sit on; buttocks
小圆面包；人的臀部
In use
He fell off his bike and landed right on his buns.
After sitting on the hard bench for hours, my buns were sore.
The toddler waddled around in his diaper, showing off his little buns.
have nice buns
常用于称赞或追求身材。
He works out every day to have nice buns.
他每天都在锻炼，为了拥有好看的臀部。
get off one's buns
俚语，表示‘别坐着不动’。
You've been sitting all day; get off your buns and take a walk.
你坐了一整天了，起来走走。
move one's buns
俚语，意为‘赶快’。
Move your buns or we'll be late!
快点，不然我们要迟到了！
Common mistakes
I ate two bun for breakfast.I ate two buns for breakfast.
buns 是可数名词复数形式，表示多个小圆面包时必须加 -s，单数 bun 不能表示复数。
I slipped and hurt my bun.I slipped and hurt my buns.
在俚语中表示臀部时，通常使用复数形式 buns，单数 bun 不表示这个意思。
I need to buy buns for sandwiches.I need to buy bread for sandwiches.
buns 特指小圆面包，而三明治通常使用切片面包（bread），除非特别指定用圆形面包做三明治，否则使用 bread 更恰当。
Connections
Learner notes
Grammar Note
When meaning 'buttocks', used only in plural form; as 'small bread rolls', it is the plural of 'bun'.
Dictionary facts from ECDICT, WIKTIONARY.