Green’s Dictionary of Slang

1. a receiver and seller of stolen property.

1609		Dekker Gul’s Horne-Booke 8: He shall strait waies be [...] tane in his own purse-nets by fencers and cony-catchers.
1678		Four for a Penny 3: He is the Treasurer of the Thieves Exchequer, the Common Fender [sic] of all Bulkers and Shop-lifts in the Town.
1728		Defoe Street Robberies Considered 32: Fencer, Receiver of stolen Goods.
1753		J. Poulter Discoveries (1774) 42: I am a Locker, and a Dudder, and Fencer of Slop; I leave Goods at a House, and borrow Money on them, pretending they are Rum Goods, Goods made in London, and sell Tea.
1786		Whole Art of Thieving [as cit. 1753].
1829		Sydney Gaz. 11 Apr. 3/3: I have been preyed upon by sharks, sharpers, flash-men, fencers, rum coves, squatters, nippers, lifters, and all the tag-rag-and-bobtail denoted by the worst words in the Slang Dictionary.
1832		Public Ledger 12 Nov. 3/3: Receivers of stolen goods Fencers.
1855		W. Phillips Wild Tribes of London 70: This, you see, is a fence-house; and those what we call Petticoat-lane fencers.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1864, 1867, 1870		Hotten Sl. Dict.
1901		J. Flynt World of Graft 91: Mother Mandelbaum was the most prominent ‘fencer’ New York has ever had.

2. (UK tramp) a door-to-door hawker.

1929

Advertiser (Adelaide) 25 Oct. 32/8: No ‘maunderer’ (tramp) nor ‘fencer’ (door to door hawker) need ‘clem’, (starve), or do without ‘chow chow’ (food) if he follows the many ‘patterans’ (private marks) which tramps make on or near the doors of generous householders.