Green’s Dictionary of Slang

1. a railway train.

1910

Eve. Teleg. (Dundee) 3 Aug. 4/1: Owing to the 'Christmas' [...] the 'Andie' waited several minutes at the junction [...] 'Christmas card' (guard), 'Andie Caine' (train).

2. rain.

1932		‘P.P.’ Rhy. Sl.
1960		J. Franklyn Dict. of Rhy. Sl. 32/1: Andy Cain Rain Of late 19C. origin.
1971		J. Jones Rhy. Cockney Sl.
2002		D. Shaw ‘Dead Beard’ at www.asstr.org 🌐 I love the smoke but it’s hard to take when it’s dark and boris bold, and the andy cain is pissing down.