Green’s Dictionary of Slang

1. stealing from carts or vans.

1812		Vaux Memoirs in McLachlan (1964) 82: Lest the reader should be unprovided with a cant dictionary, I shall briefly explain in succession: viz., dragging [...] Robbing carts, or carriages, of bales, trunks, &c.
1833		[T. Wontner] Old Bailey Experience 115: A man was committed for robbing, or attempting to rob, a cart, in the street, (what is called ‘dragging’).
1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1870		(con. 1800s) Leeds Times 7 May6/6: These youths practised [...] thirteen different ‘lays’ including [...] ‘dragging,’ or cutting trunks off carriages.
1873		Sl. Dict. 149: Dragging robbing carts, &c. by means of a light trap which follows behind laden vehicles. Cabs are sometimes eased of trunks in this way, though it is hard to say whether with or without the complicity of the cabmen.
1931		‘English Und. Sl.’ in Variety 8 Apr. n.p.: Dragging — Stealing parcels from back of van.
1938		F.D. Sharpe Sharpe of the Flying Squad 330: dragging : Stealing from vans.
1989		J. Morton Lowspeak.

2. (US Und.) to steal goods deposited in shop doorways; thus dragging n.

1859

Matsell Vocabulum 27: dragging Stealing from shop-doors.

3. (Aus. / US Und.) to rob on the street, to ‘mug’; thus dragging n.

1901		W.S. Walker In the Blood 143: I scorn to ‘flimp’ or ‘hold,’ on ‘dragging’ I ain’t bold. [Ibid.] 158: ‘Dew-dropping,’ ‘dragging down’ or ‘flimpings’ more in our line.
1965		(con. 1950s) H. Williamson Hustler 116: At this time in that neighborhood they had a special type of hustlin’ called ‘draggin’. That mean, we’d go a certain distance out of the neighborhood and we’d rob everybody we’d meet.

4. stealing from parked motor cars.

1935		R.T. Hopkins Life and Death at the Old Bailey 62: ‘Dragging’ is patrolling in a stolen car to carry out petty larcenies from parked motor cars.
1956		‘Charles Raven’ Und. Nights 86: The basic art of dragging is to act as if you owned the car and act quickly.