bun

n. sweet roll, any of various bread rolls; twist of hair worn at the back of the head

(Medicine) waste product created during the metabolic process and excreted into the blood (can be used as an indication of renal function)

A bun is a sweet or plain small bread or a round roll. It can be consumed as-is, made into a sandwich, or or designed to be cut in half and filled with ingredients. "Bun" can also refer to a kind of filled dumpling, such as Chinese baozi.
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The blood urea nitrogen (BUN) test is a measure of the amount of nitrogen in the blood that comes from urea.  Urea is a substance secreted by the liver, and removed from the blood by the kidneys.
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BUN blood urea nitrogen; see urea nitrogen. BUN abbr. blood urea nitrogen Blood urea nitrogen A waste product that is formed in the liver and [more]Bun - Community and Resources

Noun
1. small rounded bread either plain or sweet
(synonym) roll
(hypernym) bread, breadstuff, staff of life
(hyponym) tea bread

n. corf