Bur

UK: /bɜː/ US: /bɝ/ ,(bûr)

WordReference Random House Learner's Dictionary of American English © 2025

bur¹ /bɜr/   n. [countable]

1. Plant Biology a prickly case around the seeds of certain plants, as the chestnut.
2. Plant Biology any bur-bearing plant.
3. Mechanical Engineering burr¹ (defs. 1, 3).
4. Dentistry a rotary cutting tool like a drill.

bur.,  an abbreviation of:

1. bureau.

WordReference Random House Unabridged Dictionary of American English © 2025

bur¹  (bûr), n., v., burred, bur•ring. 
n. 

1. Plant Biology a rough, prickly case around the seeds of certain plants, as the chestnut or burdock.
2. Plant Biology any bur-bearing plant.
3. something that adheres like a bur.
4. Mechanical Engineering [Mach.] burr¹ (defs. 1, 3).
5. Dentistry a rotary cutting tool usually of steel or other hard metal shaped into a shank and a head, for removing carious material from teeth and preparing cavities for filling.
6. Surgery a cutting tool resembling that of a dentist, used for the excavation of bone.

v.t. 

7. to extract or remove burs from.

• Middle English burre, apparently cognate with Danish burre, Norwegian, Swedish borre bur 1300–50

bur²  (bûr), n. 

1. Metallurgy burr².

Bur., 

1. Place Names Burma.

bur., 

1. bureau.

Collins Concise English Dictionary © HarperCollins Publishers::

bur / bɜː/ noun

1. a seed vessel or flower head, as of burdock, having hooks or prickles
2. any plant that produces burs
3. a person or thing that clings like a bur
4. a small surgical or dental drill

verb (burs, burring, burred)

1. (transitive) to remove burs from

Also (for senses 1–4): burr Etymology: 14th Century: probably of Scandinavian origin; compare Danish burre bur, Swedish kardborre burdock