Green’s Dictionary of Slang

1. (also finger) rum.

1856		H. Mayhew Great World of London I 5: Splodger, will you have a Jack-surpass of finger-and-thumb.
1859, 1860		Hotten Dict. of Modern Sl. etc.
1877		J. Diprose London Life 74: [as cit. 1856].
1886		Sporting Times 9 Jan. 5/4: When he mixed rum and milk, he begged pardon, Finger and Pimlico.
1893		P.H. Emerson Signor Lippo 48: I always indulge in a little brian or finger in my bohee. Saturday you see is pay day, so I always get a drop for me and old Bottle Nose then.
1902		Dundee Courier 14 June 7/2: ‘Finger and thumb’ means rum.
1910		Eve. Teleg. (Dundee) 3 Aug. 4/1: He orders a 'lord's worth' (Lord of the manner [sic]) of 'finger and thumb'.
1925		(con. WWI) Fraser & Gibbons Soldier and Sailor Words 94: Finger And Thumb: Rum.
1932		‘P.P.’ Rhy. Sl.
1944		Maurer & Baker ‘“Aus.” Rhyming Argot’ in AS XIX:3.
1969		S.T. Kendall Up the Frog.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
2002		B. Kirkpatrick Wicked Cockney Rhy. Sl.

2. a road [= drum n.² ].

1862		Worcs. Chron. 12 Nov. 4/1: When we touched for it, we had to get on the finger and thum [sic] a few miles. We durst not get on the rattles.
1937–84		Partridge DSUE (1984) 392/2: late C.19–20.
1960		J. Franklyn Dict. of Rhy. Sl.

3. a friend [= chum n. (1)].

1984		Partridge DSUE (8th edn) 392/2: since ca. 1930.
2002		B. Kirkpatrick Wicked Cockney Rhy. Sl.

4. one’s mother; thus mum adj., quiet [SE mum in SE and colloq. uses].

2002		B. Kirkpatrick Wicked Cockney Rhy. Sl. 30: finger and thumb [...] keep quiet (informal mum).
2002		M. Coles More Bible in Cockney 52: Mary the finger-and-thumb of Jesus.

5. a drum.

2002

B. Kirkpatrick Wicked Cockney Rhy. Sl.