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  1. a rough, prickly case around the seeds of certain plants, as the chestnut or burdock.
  2. any bur-bearing plant.
  3. something that adheres like a bur.
  4. Machinery. 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.
verb (used with object), burred, bur·ring.
  1. to extract or remove burs from.

Origin of bur1

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


  1. burr2.


  1. Also buhr. a protruding, ragged edge raised on the surface of metal during drilling, shearing, punching, or engraving.
  2. a rough or irregular protuberance on any object, as on a tree.
  3. a small, handheld, power-driven milling cutter, used by machinists and die makers for deepening, widening, or undercutting small recesses.
  4. a lump of brick fused or warped in firing.
verb (used with object)
  1. to form a rough point or edge on.
  2. deburr.
Also bur (for defs 1, 3).

Origin of burr1

First recorded in 1605–15; spelling variant of bur1


or bur

  1. a washer placed at the head of a rivet.
  2. a blank punched out of a piece of sheet metal.

Origin of burr2

1375–1425; late Middle English burrewez (plural), buruhe circle, variant of brough round tower; see broch


  1. bureau.


  1. Burma.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

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British Dictionary definitions for bur


  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
  5. a variant spelling of burr 3, burr 4
verb burs, burring or burred
  1. (tr) to remove burs from
Also (for senses 1–4): burr

Word Origin

C14: probably of Scandinavian origin; compare Danish burre bur, Swedish kardborre burdock


abbreviation for
  1. Myanmar (international car registration)

Word Origin

from Burma


abbreviation for
  1. Myanmar (Burma)


  1. Aaron . 1756–1836, US vice-president (1800–04), who fled after killing a political rival in a duel and plotted to create an independent empire in the western US; acquitted (1807) of treason


  1. a small power-driven hand-operated rotary file, esp for removing burrs or for machining recesses
  2. a rough edge left on a workpiece after cutting, drilling, etc
  3. a rough or irregular protuberance, such as a burl on a tree
  4. British a burl on the trunk or root of a tree, sliced across for use as decorative veneer
noun, verb
  1. a variant spelling of bur
verb (tr)
  1. to form a rough edge on (a workpiece)
  2. to remove burrs from (a workpiece) by grinding, filing, etc; deburr

Word Origin

C14: variant of bur


  1. phonetics an articulation of (r) characteristic of certain English dialects, esp the uvular fricative trill of Northumberland or the retroflex r of the West of England
  2. a whirring sound
  1. to pronounce (words) with a burr
  2. to make a whirring sound

Word Origin

C18: either special use of bur (in the sense: rough sound) or of imitative origin



  1. a washer fitting around the end of a rivet
  2. a blank punched out of sheet metal

Word Origin

C16 (in the sense: broad ring on a spear): variant of burrow (in obsolete sense: borough)


buhr or bur

  1. short for buhrstone
  2. a mass of hard siliceous rock surrounded by softer rock

Word Origin

C18: probably from bur, from its qualities of roughness
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for bur


"prickly seed vessel of some plants," c.1300, burre, from a Scandinavian source (cf. Danish borre, Swedish hard-borre, Old Norse burst "bristle"), from PIE *bhars- (see bristle (n.)). Transferred 1610s to "rough edge on metal," which might be the source of the sense "rough sound of the letter -r-" (see burr).



"rough sound of the letter -r-" (especially that common in Northumberland), 1760, later extended to "northern accented speech" in general. Possibly the sound of the word is imitative of the speech peculiarity itself, or it was adapted from one of the senses of bur (q.v.), perhaps from the phrase to have a bur in (one's) throat (late 14c.), which was a figure of speech for "feel a choking sensation, huskiness." OED says the Scottish -r- is a lingual trill, not a true burr.

Online Etymology Dictionary, © 2010 Douglas Harper

bur in Medicine


  1. A rotary cutting instrument used in dentistry for excavating decay, shaping cavity forms, and reducing tooth structure.
  2. A drilling tool for enlarging a trephine hole in the cranium.


  1. Variant ofbur

bur in Science


  1. A type of pseudocarp in which the outer surface possesses hooks or barbs. Burs become caught in the feathers or hair of animals, which then carry them away to disperse the seeds.