Green’s Dictionary of Slang

a term of address, generally affectionate or friendly.

a.1674		‘Canting Song’ Head Canting Academy (1674) 24: Away sweet Ducks with greedy eyes / From London walk up Holbourn.
1754		Scoundrel’s Dict.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor III 134/1: Ah! you little ducksey, ducksey, ducksey!
1876		A.B. Sedgwick My Walking Photograph 12: Good-bye, my ducksy-pucksy!
1908		Sporting Times 13 June 1/5: ‘Never mind, ducks,’ said dear little Mrs. Pitcher.
1910		N.Z. Truth 16 Mar. 7/3: These disreputable residents are of the female gender and they lean over the front gate of evenings and say ‘Good-night, duckie’ to perfect strangers .
1911		Gem 23 Sept. iii: Well, you won’t be here long, duckie; at the next station out you go.
1926		Breton & Bevir Adventures of Mrs. May 108: Same ’ere, old ducks.
1938		(con. 1900s) J.B. Booth Sporting Times 138: Stand me a cab fare, duckie / Oh! do, now, there’s a dear.
1938		J. Curtis They Drive by Night 62: Give us a light, ducks.
1938		X. Herbert Capricornia (1939) 69: Goodby lovey-ducks — tata pretty dear.
1943		Mass-Observation Report on Juvenile Drinking 11: The waiter comes up to Inv. and says, ‘What would you like, duck?’.
1948		C. Day Lewis Otterbury Incident 110: Name it, ducks, you shall have it.
1957		J. Braine Room at the Top (1959) 104: Honestly, ducks, they can’t understand the simplest thing.
1968		P. Barnes Ruling Class II vi: That’s right, ducks. ’Ow’s about it?
1973		(con. 1927–30) E. Williams Emlyn 111: I’m thirty-five, ducks, but wi’ slap on me face and a spot of surprise pink in the floats I can get away wi’ twenty.
1978		A. Burgess 1985 (1980) 165: If yer don’t go, ducks, yer gets beat up proper.
1991		J. Osborne Déjàvu Act II: Well, lets have something cheerful, ducks.
1997		P. Theroux Kowloon Tong 173: Stop faffing around and come along. You too, duckie.