Green’s Dictionary of Slang

1. to idle, to hang around aimlessly.

1956

‘Raymond Thorp’ Viper 66: That hot summer, the afternoons ligging in a quiet square, the drinking sessions, the balls with cats and chicks.

2. to sponge, to ‘freeload’, to gatecrash functions or parties, esp. those connected with show business; thus ligging n. and adj.

1956		‘Raymond Thorp’ Viper 40: Now I’m tired man. Just ligging around [Ibid.] 46: Denis wasn’t alone in Soho in wanting to lig his way through llife.
1960		C. MacInnes ‘The Other Man’ in England, Half Eng. (1961) 142: The ponce’s air of having a function [...] which totally distinguishes him from the mere ‘ligging’ layabout.
1961		T. Taylor Baron’s Court All Change (2011) 33: [D]istributing the spliffs to the various groups that were ligging about.
1997		Share Slanguage.
1999		Guardian Rev. 3 July 11: I was unprepared for the glamorous life of the Guardian writer – Babycham before breakfast, ligging at top Stanford Hill nightspots, shagging minor royals.
2000		Guardian Rev. 19 Feb. 4: Don doesn’t get a chance to make his ligging debut in the end.