Green’s Dictionary of Slang

1. a hearty meal; more usu. tuck-in n. or tuck-out n.¹

1844

J.T.J. Hewlett Parsons and Widows (1857) 115: We meant to save all our money for the tuck.

2. a hearty appetite.

1838

W. Holloway Dict. Provincialisms 178: ‘He has a pretty good Tuck of his own’, means that a man is a great eater. Hants. Sussex.

3. (mainly juv.) food, esp. sweet cakes and pastries; also attrib.

1835		G. Kent Modern Flash Dict. 34: Tuck – victuals.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].
1857		T. Hughes Tom Brown’s School-Days (1896) 240: He didn’t take much exercise and ate too much tuck.
1862		F.W. Farrar St Winifred’s (1863) 351: Coles’ was the favorite ‘tuck-shop’ of the boys.
1873		Sl. Dict.
1882		‘F. Anstey’ Vice Versa (1931) 58: Why, what did you go and sneak of him for bringing tuck back to school for, eh?
1890		H. Lawson ‘The Song of Old Joe Swallow’ in Roderick (1967–9) I 75: An’ pertaters dipped in honey was the only tuck we had.
1897		E.W. Townsend Chimmie Fadden 1: I’ve seed her feeding dem kids what gets free tuck on Christmas by dose east side missioners.
1901		Boy’s Own Paper 26 Jan. 262: I was hard up, and hadn’t had any tuck for a fortnight.
1919		Marvel 1 Mar. 6: Filled with tuck.
1922		‘J.H. Ross’ Mint (1955) 73: We [...] bought ourselves a mess-tin of tea and three sausage rolls [...] Creagh, being ex-officer, was over nice for tuck.
1940		M. Marples Public School Slang 180: tuck: the classical school slang expression for food of the edible kind, not provided by the authorities. Such food is generally sold in tuck-shop [and] kept in a tuck-box [...] the earliest form in which it appears is tuck-out (=a hearty meal), and it has been suggested that it denotes a meal which removes the tucks or creases from the trousers or waistcoat.
1950		A. Buckeridge Jennings Goes To School 30: You mustn’t eat tuck before lunch.
1961		‘Frank Richards’ Billy Bunter at Butlins 6: In matters of tuck, the fat Owl of the Remove had no scruples.
1999		Beano 18 Sept. n.p.: The Friar let me share his tuck.
2012		D. O’Donnell Locked Ward (2013) 326: Adequate tuck here, thanks.

4. (UK Und.) a successful robbery.

1977

G.F. Newman Villain’s Tale 34: ‘What’s he do, Mickey?’ ‘Armed blags is what I hear – s’posed to be one or two nice little tucks down to him what he didn’t go for.’.