"short and stout," 1750, apparently from some noun sense of dump (compare dumpling), but the connection is unclear.

Old English dunn "dingy brown; dark-colored," perhaps from Celtic (compare Old Irish donn "dark;" Gaelic donn "dull; dark brown; dark;" Welsh dwnn "brownish"), from PIE *donnos, *dusnos "dark." As a noun, "dun color," 1560s; as "a dun horse" from late 14c. The "horse" meaning is that the figurative expression dun is in the mire "things are at a standstill or deadlocked," which occurs in both Chaucer and Shakespeare. Dun also is likely the origin of the surnames Dunn, Dunne, Donne, Dunning, etc.

"to insist on payment of debt," 1620s, also as a noun, "agent employed to collect debts," of uncertain origin, perhaps related to Middle English dunnen "to sound, resound, make a din" (c. 1200, dialectal variant of din), or shortened from dunkirk (c. 1600) "privateer," a private vessel licensed to attack enemy ships during wartime, from Dunkirk, the French port from which they sailed. The oldest theory traces it to a Joe Dun, supposedly a London bailiff famous for catching defaulters. Related: Dunned; dunning. As a noun from 1620s.

surname and masc. given name, from Gaelic donn "brown, dark" (see dun (adj.)) + ceann "head." Or else from Old Irish, Old Gaelic Donnchad "brown warrior."

"dullard, dolt, ignoramus," 1570s, from earlier Duns disciple, Duns man (1520s) "follower of John Duns Scotus" (c. 1265-1308), Scottish scholar of philosophy and theology supposed to have been born at Duns in Berwick. His followers, the Scotists, had control of the universities until the Reformation. By 1520s, humanist reaction against medieval theology had singled him out as the type of the hairsplitting scholastic. It became a general term of reproach applied to obstinate or sophistical philosophical opponents by 1520s, then by 1570s it was extended to any dull-witted student. Dunce's cap is attested by 1792 (compare foolscap).

"dunce, numbskull," 1620s, from head (n.); the first element is obscure; perhaps from Middle Dutch doner, donder "to thunder" (compare blunderbuss). Dunder also was a native dialectal variant of thunder. In the same sense were dunder-whelp (1620s); dunderpate (1754); dunderpoll (1801).

1867, Dundreary whiskers, long, bushy sideburns without a beard, resembling those worn by actor E.A. Sothern (1826-1881) while playing Lord Dundreary, the witless, indolent character in English dramatist Tom Taylor's play "Our American Cousin" (1858).

"mound, ridge, or hill of loose sand heaped up by the wind near the coast of a sea," 1790, from French, Middle Dutch or Middle Low German dune, all of which are perhaps from Gaulish *dunom (making it cousin to down (n.2) "small, rounded hill").

The French dune "sand hill" (13c.) is held by Diez to be an Old French borrowing from Dutch duin or some other Germanic source. Italian and Spanish duna are from French. The English word is perhaps also partial a dialectal form of down (n.2). Dune buggy, "recreational motor vehicle designed for use on beaches," is attested by 1965.

late Old English dung "manure, decayed matter used to fertilize soil," from Proto-Germanic *dungō (source also of Old Frisian and Old Saxon dung "manure;" Old High German tunga "manuring," tung "underground room covered with manure;" German Dung; Old Norse dyngja "heap of manure, women's apartment;" Swedish dynga "dung, muck;" Danish dynge "heap, mass, pile"), perhaps from a PIE *dhengh- "covering" (source also of Lithuanian dengti "to cover," Old Irish dingim "I press").

The word recalls the ancient Germanic custom (reported by Tacitus) of covering underground shelters with manure to keep in warmth in winter. The meaning "animal excrement," whether used as fertilizer or not, is from late 13c.

It appears that the whole body of journeymen tailors is divided into two classes, denominated Flints and Dungs: the former work by the day and receive all equal wages; the latter work generally by the piece ["The Annual Register for the Year 1824," London, 1825].

Dung beetle, common name of the beetles which roll up balls of dung," is attested by 1630s. In colloquial American English, tumble-bug. An Old English word for it was tordwifel "turd weevil."

"to cover with manure," Middle English dungen, from Old English gedyngan, from the noun (see dung (n.)). Related: Dunged; dunging.