Green’s Dictionary of Slang

(Aus./N.Z.) a friendless male.

1999		G. Seal Lingo 105: A nigel or a scott is an awkwardly alone male at social gatherings.
2001		Sydney Morning Herald (Aus.) 6 Jan. n.p.: So here’s a tentative guide to Sydney teenspeak: [...] A nigel (a friendless person).
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 124/1: Nigel n. an inmate who never receives a visit from friends or family.