Green’s Dictionary of Slang

1. an expatriate, any citizen of one country living abroad; also attrib.

1958		C. Lee diary 8 May in Eight Bells & Top Masts (2001) 116: He keeps talking about people called expats. Seems they’re the British who live here.
1962		D.J. Enright in Times Literary Supplement 10 Aug. 582: (title of poem) Expat .
1983		(con. 1950s) D. Nobbs Second From Last in the Sack Race 259: Uncle Teddy refuses to behave like a typical ex-pat!
1985		B. Humphries Traveller’s Tool 110: A carefully orchestrated shit-slinging campaign by a few élitist ex-pats, traitors and plummy-voiced kapok-krunchers who make a quid in the colour supplements by bucketing their bushland heritage.
1999		Indep. Mag. 12 June 8: Ex-pat antipodeans.
2000		Observer Escape 9 Jan. 3: A plethora of expats drinking gin and tonic.
2012		L. Berney Whiplash River [ebook] ‘Some rich expat asshole’.
2013		K. Sampson Killing Pool 45: I sunk myself in with the expat community in Torreblanca.

2. (W.I.) an immigrant, esp. a white foreigner, working in a local job.

1974

cited in Allsopp Dict. Carib. Eng. Usage (1996).