'BUN' definitions:

Definition of 'bun'

From: WordNet
noun
Small rounded bread either plain or sweet [syn: bun, roll]

Definition of 'BUN'

From: GCIDE
  • BUN \BUN\ n. [acronym] (Med.) same as
  • blood urea nitrogen; the concentration of nitrogen in blood present in the form of urea; -- used as a measure of kidney function.
  • Note: Blood usually contains 10 to 15 mg of nitrogen per 100 ml in the form of urea. --Stedman. [PJC]

Definition of 'Bun'

From: GCIDE
  • Bun \Bun\, Bunn \Bunn\, n. [Scot. bun, bunn, OE. bunne, bonne; fr. Celtic; cf. Ir. bunna, Gael. bonnach, or OF. bugne tumor, Prov. F. bugne a kind of pancake; akin to OHG. bungo bulb, MHG. bunge, Prov. E. bung heap, cluster, bunny a small swelling.]
  • 1. any of a variety of slightly sweetened or plain raised cakes or bisquits, often having a glazing of sugar and milk on the top crust; as, a hot cross bun. [1913 Webster +PJC]
  • 2. a type of coiffure in which the hair is gathered into a coil or knot at the top of the head. [PJC]
  • 3. pl. the buttocks. [slang] [PJC]