ligger, n. — Green’s Dictionary of Slang

ligger n.

also lig

[ety. debatable: acronym of least important guest or SE linger, to hang around, or Banffshire dial. lig, to gossip, to talk too much. Most likely it is dial. lig, to lie around. The term became widespread in the early 1970s, but dates at least to 1960 when Colin MacInnes (1914–76) used it in his essay on poncing — ‘The Other Man’]

a hanger on, esp. in show business, a ‘freeloader’, also attrib.

1960		A. Burgess Doctor Is Sick (1972) 172: Furniture-fracturer, / Light-hearted ligger, / Counterfeit cashman.
1977		L. Bangs in Psychotic Reactions (1988) 255: That guy was a bleedin’ little ligger.
1984		Partridge DSUE (8th edn) 681: lig [...] one who takes [...] advantage of free drinks: ‘pop’ music, media, journalistic: since earlier 1980s.
1986		B. Geldof Is That It? 258: Paul’s only allowed her admittance to the friends’, liggers’ and freeloaders’ enclosure.
1997		N. Barlay Curvy Lovebox 149: I get that feelin’ of bein’ a ligger at somone else’s do.
2000		Indep. on Sun. Reality 27 Feb. 29: I am a ligger and a fanzine writer in the rock fraternity.
2011		J.J. Connolly Viva La Madness 74: Liggers who love a scoundrel and the dear-departed’s kith and kin.
2021		S. Ditum https://upskirtchronicles.substack.com 8 Sept. 🌐 Did the offended readers nobly eschew jokes about Harding’s ligger days at the time?