Green’s Dictionary of Slang

moonlight n.

1. smuggled spirits [var. on moonshine n.].

[UK]Hotten Dict. of Modern Sl. etc. (2nd edn).
[UK]Hotten Sl. Dict.
[Scot]Eve. Teleg. (Dundee) 1 Sept. 3/6: The language of the London East-end pub [...] ‘Moonlight’ — smuggled spirit.

2. see moonlight flit n.

SE in slang uses

In compounds

In phrases

moonlight on the lake (n.)

(US) poached egg on corned beef hash.

[US]S.F. Call 9 Jan. 6/5: ‘Moonlight on the lake’ had a lot more poetry in it than plain ‘poached egg on corned beef hash’.