bun /bʌn/ noun [countable]
[Sense 1-3, 5: Date: 1300-1400; Origin: Perhaps from Old French bugne 'swelling (caused by a blow), type of fritter']
[Sense 4: Date: 1800-1900; Origin: Perhaps from Scottish Gaelic bun; ⇒ bunny]

1. British English a small round sweet cake:
a sticky bun

2. a small round type of bread:
a hamburger bun

3.
if a woman has her hair in a bun, she fastens it in a small round shape at the back of her head

4. buns [plural] American English informal the two round parts of a person’s bottom Synonym : buttocks

5. have a bun in the oven British English informal to be pregnant – used humorously

[TahlilGaran] Dictionary of Contemporary English ▲

bun
noun
I. small round cake
ADJ. fresh | stale | cinnamon, cream, currant, hot cross, iced, sticky | hamburger
VERB + BUN eat, have | bake, make
 ⇒ Special page at FOOD

[TahlilGaran] Collocations Dictionary ▲

bun
II. hair fastened in a round shape
ADJ. neat, severe, tight | loose
PREP. in a ~ a woman with her hair in a loose bun
PHRASES pull/draw your hair back in(to) a bun Her black hair was drawn back into a neat bun.
tie your hair (back) in a bun, wear your hair in a bun

[TahlilGaran] Collocations Dictionary ▲