Green’s Dictionary of Slang

1. a woman, esp. when good-looking, even showy [the image of a duchess as an imposing figure].

c.1698		B.E. Dict. Canting Crew.
1902		Ade Girl Proposition 69: If he had a Duchess on his Staff he would lead her along the main-travelled Streets and show her off.
1911		E. Dyson ‘On a Bender’ in Benno and Some of the Push 77: Afore the fat Duchess ’d begun t’ pull the drinks Benno fell inter one iv them cold, dank, solemn spasms.
1915		N.Z. Truth 28 Aug. 7/7: Seth [...] raised his roof to the duchess, and passed on.
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 254: dutchess (n.): girl.
1960, 1975		Wentworth & Flexner DAS 165/2: duchess n. 1. A girl; esp. a snobbish or aloof girl. 2. A girl who is in the know or who belongs to a jive or underworld group. 3. A female member of a street gang.
1989		M. Amis London Fields 77: The girls, they come around the whole time. [...] These pictures and visions, little duchesses, dazzlers and poules de luxe.

2. an old woman.

1705–07		N. Ward Hudibras Redivivus I:5 16: Next these, came a fore-leg’d Dutches, / Grunting and whining on her Crutches.
1842		Bell’s Penny Dispatch 27 Mar. 3/3: ‘Don’t look black," he confirmed, turning to [Mother] Emerson [...] ‘you shall go too, my duchess’.
1878		C. Hindley Life and Times of James Catnach 129: A surly old duchess, with one of her crutches, / Had floor’d a blindman for capsizing her ale.

3. a prostitute.

1773

O. Goldsmith She Stoops to Conquer Act II: This stammer in my address [...] can never permit me to soar above the reach of a milliner’s ’prentice, or one of the duchesses of Drury-lane.

4. a general term of address to a woman.

1860		R. Nicholson Rogue’s Progress (1966) 77: ‘Duchess,’ said Hawthorne (he always called the lady ‘the duchess’), ‘have you tried a nosegay?’.
1880		Henley & Stevenson Deacon Brodie III tab.V ii: smith: No, Duchess, he has not good manners. jean: Ay, he’s an impident man.
1942		N. Algren Never Come Morning (1988) 77: Walk faster, Duchess [...] I got t’ get t’ bed some time.
1953		K. Tennant Joyful Condemned 272: Hold your noise, Duchess.
1975		J. Roe The Same Old Grind 119: ‘You know, my duchess, that it never will [i.e. arrive]’.

5. (Aus.) a procuress, a brothel-keeper.

1900		Truth (Sydney) 9 Dec. 7/3: Girls we know is frequent tempted, / Being weak, to go astray; / But they don't want no old Duchess / For to show / no girls the way.
1904		Truth (Sydney) 10 July 1/2: For this piece of dirty work they / Gets paid five & twenty quid / From the Duchess keepin’ ’ouse.

6. one’s mother.

1909

J. Ware Passing Eng. of the Victorian Era 119/2: Duchess (Peoples’). Mother – invariable title given between familiar friends when the mother of either is being asked after. ‘How’s the Duchess, Bob?’.

7. a woman who is making money in films.

1935

L.A. Times 24 Mar. II 1/7: DUCHESS: A chorine with a fur coat or other evidence of material wealth. There are many Duchesses.

8. an ageing, affected male homosexual.

1972		B. Rodgers Queens’ Vernacular 69: duchess (pej) one who falsely assumes grand airs.
1979		Maledicta III:2 222: Cinderella becomes Old Ella, the whining failure or whoring harridan, derisively hailed as madame, countess, duchess (if pissy, piss-elegant).
1980		Maledicta IV:2 (Winter) 226: The bitchiness often attributed to fags from tender chicken to grand-dame duchesses surfaced in Miss Thing.
2019		P. Baker Fabulosa 292/1: duchess a rich or grand gay man.