From earlier dugge ("pap, teat"; compare also English dialectal ducky, dukky (“the female breast”)), apparently connected to Danish dægge (“to suckle”), Swedish dägga (“to suck”), Old English dēon (“to suckle”). More at doe.
Compare also doug.
Meanings
(in-plural) A mammary gland on a domestic mammal with more than two breasts, mostly used to refer to the nipples of non-ruminants and non-primates.
Horatio: This Lapvving runs avvay vvith the ſshell on his head.
Hamlet: He did complie with his Dugge before hee ſuck't it: […] c. 1599–1602 (date written), William Shakespeare, “The Tragedie of Hamlet, Prince of Denmarke”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act V, scene ii], page 280, column 1:
First Pig.
I suck, but no milk will come from the dug. 1820, Percy Bysshe Shelley, Oedipus Tyrannus; Or, Swellfoot The Tyrant: A Tragedy in Two Acts:
(in-plural, vulgar) A woman's breast or nipple.
Ah! that Deceit ſhould ſteale ſuch gentle ſhape,
And vvith a vertuous Vizor hide deepe vice.
He is my ſonne, I, and therein my ſhame,
Yet from my dugges, he drew not this deceit c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act II, scene ii], page 183, column 2: