"A coarse cotton stuff, generally blue, worn by sailors" [Century Dictionary, 1897], 1610s, dongerijns, from Hindi dungri "coarse calico," said to be from the name of a village, now one of the quarters of Bombay. Dungarees "trousers made of dungaree" is by 1868.

c. 1300, "great tower of a castle," from Old French donjon "great tower of a castle" (12c.), from Gallo-Roman *dominionem, from Late Latin dominium, from Latin dominus "master" (of the castle), from domus "house" (from PIE root *dem- "house, household"), so called probably for its commanding position or strength. Sense of "castle keep" led to that of "strong (underground) cell" in English early 14c. The original sense went with the variant donjon.

"a heap of dung," early 14c., from dung (n.) + hill (n.).

1919, "to dip (something) into a beverage or other liquid," American English, from Pennsylvania German dunke "to dip," from Middle High German dunken, from Old High German dunkon, thunkon "to soak," from PIE root *teng- "to soak" (see tincture). The basketball sense "jump up and push (the ball) down through the basket" is recorded by 1935 as a verb (implied in dunking), 1967 as a noun (earlier dunk shot, 1950). Related: Dunked.

popular name of a German-American Anabaptist sect, 1756, from (Pennsylvania) German Tunker, from tunken, dunken "to dip, soak" (see dunk (v.)). So called because they practice adult baptism by triple immersion. The proper name is Brethren.

a representation of a colloquial pronunciation of "(I) don't know," 1842, American English.

1580s, "song for two voices, duet," via either Italian or French from Latin duo "two" (from PIE root *dwo- "two"). Meaning "two people" (especially as an entertainment team) attested by 1887.

"reckoning by twelves and powers of twelve," 1714, from Latin in duodecimo (folded) "in a twelfth" of a sheet, from ablative of duodecimus "twelfth" (from duodecim "twelve;" see dozen) + -al (1).

size of paper or page (more or less 6.5 to 7.5 inches high and 4.5 inches wide), 1650s, from Latin in duodecimo (folded) "in a twelfth" of a sheet, from ablative of duodecimus "twelfth," from duodecim "twelve" (see dozen). So called because made originally by folding a printer's sheet and cutting it in 12 leaves. Often abbreviated 12mo. Also "a book in which each page is the twelfth part of the printer's sheet." Related: Duodecimary.