Green’s Dictionary of Slang

(Aus./UK Und.) a person who steals washing that is hanging out to dry.

1826		Morn. Chron. (London) 22 Aug. 3/1: A common snow-dropper.
1847		G.W.M. Reynolds Mysteries of London III 85/1: A Stranger—looked like a snow-dropper. Twelve mill-togs .
1853		Chester Chron. 25 June 6/5: ‘Snow-droppers’ are men who are endowed with the peculiar gift of transforming white hedges into green ones.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn) 222: snow droppers, rogues who steal linen from hedges and drying grounds.
1883		Manchester Courier 17 Mar. 7/4: ‘Tom the snow-dropper’ as his nom de plume implied, made it part of his business to steal linen from country hedges.
1889		Clarkson & Richardson Police! 346: ‘Snow-droppers’ are very cunning thieves. Women, as well as men, look out during the day for the best loaded ‘horse to ride on,’ in the shape of a good washing of clothes hanging out to dry.
1895		J. Caminada Twenty-Five Years of Detective Life I 12: The occupants of such houses chiefly graduated from ‘snow-droppers’ (strippers of clothes-lines) to ‘cracksmen’ (burglars).
1895		Crowe Aus. Sl. Dict. 77: Snow Dropper, one who steals linen from clothes-lines.
1901		Argus (Melbourne) 20 Sept. 6/4: Amongst these small fry of the profession [are] the Lily prigger, snow dropper or robber of clothes lines , who gets away with a roll of snow or milky duds.
1932		Sun. Mail (Brisbane) 13 Nov. 20/7: After him comes the ‘snow-dropper’ This picturesque term is used to connote the gentleman who raids clothes lines.
1935		R.T. Hopkins Life and Death at the Old Bailey 63: The following crook’s words and phrases date from the days of the old Old Bailey: [...] stealer of linen from a clothes’ line – snow dropper.
1935		Thieves Slang ms list from District Police Training Centre, Ryton-on-Dunsmore, Warwicks 10: Snow dropper: Persons who steal from clothes lines.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Snow dropper. Someone who steals from clothes lines.
2012		(con. 1980s) I. Welsh Skagboys 542: A common snowdropper’s in no position tae call any other cunt a grass.
2020		G. Disher Consolation [ebook] [O]n Canowie Place, he’d eventually nab the snowdropper.