Green’s Dictionary of Slang

1. a pub or public house.

1900		Sporting Times 26 May 2/2: How long I should be able to keep out of the pages of Weatherby’s Rub-a-dub.
1908		‘Doss Chiderdoss’ ‘Significant Strains’ Sporting Times 9 May 1/3: Uninvited, we dropped into a suburban ‘rub-a-dub.’.
1910		Eve. Teleg. (Dundee) 3 Aug. 4/1: He puts on a clean 'Oxford,' changes his 'almonds,' brushes his 'Barnet,' and dons his 'turtles.' He then pays a visit to the 'rub-a-dub'.
1920		‘Doss Chiderdoss’ ‘No Separation’ in Sporting Times 3 Jan. 1/3: Tongues were busy in that ancient and accepted rub-a-dub.
1936		(con. 1900s) F. Richards Old Soldier Sahib (1965) 41: A good deal of rhyming slang was used in those days [...] a pub was a ‘rub-a-dub.’.
1937		West. Argus (Kalgoorlie, WA) 6 July 17/1: Wifey said she felt ill and asked her spouse to go to the rubbadub for a deaner’s worth of brandy.
a.1945		L. Payne private coll. n.p.: Pub Rub-a-Dub.
1950		P. Hoskins No Hiding Place! 191/2: Rubber. Public-house .
1959		G. Slatter Gun in My Hand 165: This isn’t the rubblededub. This is the pie-cart.
1959		J. Gosling Ghost Squad 24: Thieves’ argot, spoken properly, is a foreign language which needs to be learned [...] Among the words and phrases derived from rhyming slang are: [...] rub-a-dub (pub or club).
1962		F. Norman Guntz 52: I went into this rubadub and ordered a drink at the bar.
1975		‘P.B. Yuill’ Hazell and the Three-card Trick (1977) 131: ‘It’s gone irish,’ you’ll hear people say about a rub-a-dub that’s been taken over by the big men with the pixie ears.
1982		G. Newbold Big Huey 253: rub-de-dub (n) Pub.
1998		C. Fitzpatrick ‘Gower ’98’ on Sussex University Canoe Club 🌐 Well in the rub-a-dub-dub we all got Brahms and list, some more so than others.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 156/2: rub-de-dub (also rub-a-dub) n. 2 the pub.
2003		(con. 1934) W. Woodruff Beyond Nab End 77: Sunday dinner, which was eaten at noon when the men came back from the ‘rub-a-dub’ (pub).

2. a ‘sub’ or advance on wages.

1934		John O’London’s Weekly in DSUE (1984).
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.

3. a drinking club, a social club.

1931		Framlingham Eve. News 24 Oct. 2: Other curious phrases in [...] use by criminals are ‘rub-a-dub’, club and ‘turtles,’ gloves.
1932		‘P.P.’ Rhy. Sl.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 9: Rub-a-dub: Club.
1938		F.D. Sharpe Sharpe of the Flying Squad 332: rubadub : Club.
1955		B. Hill Boss of Britain’s Underworld 12: The West End [...] was a strange place that summer’s night in 1947. The rubbers were empty.
1962		F. Norman Guntz 31: So we went to this rubadub nearby called ‘Boos.’.
1979		F. Norman Too Many Crooks Spoil the Caper 121: I knew the Williams brothers by sight, having seen them around the West End rubbadubs and shpielers.

4. (N.Z. prison) ascetic anhydride.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 156/2: rub-de-dub (also rub-a-dub) n. ascetic anhydride.