Green’s Dictionary of Slang

1. the pursuit of idling or sauntering.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.
1999		M. Coward in Verbatim 24:2 n.p.: An omipalone’s walk might be described as a mince. Mincing is less purposeful than trolling, with its echoes of ‘trawling.’.

2. the pursuit of working as a prostitute.

1986–7

Maledicta IX 143: The dolly boys of The Dilly (Piccadilly Circus) who are on the street or on the prowl in their trolling (U.S. cruising) for customers.

3. (gay) the pursuit of strolling the streets looking for possible partners.

1960		G. Westwood A Minority 208: Troll v. To look for a homosexual partner. (Used as a verb and a noun. Also trolling-ground).
1972		B. Rodgers Queens’ Vernacular 200: trolling ground (Brit gay sl) gay cruising area in a park. troll the toilet cruise the toilet.
1975		J. Wambaugh Choirboys (1976) 212: Why don’t you put on my yellow miniskirt and go out trolling. You might get lucky.
1989		R. Atkinson Long Gray Line (1990) 114: Trolling for girls was the preferred pastime.