Green’s Dictionary of Slang

(US) a sailor.

1944		P. Kendall Dict. Service Sl. n.p.: A sailor [...] swabby.
1953		L. Uris Battle Cry (1964) 119: There will be swabbies to hold the nets.
1967		(con. 1940s) M. Dibner Admiral (1968) 252: She brings us here and ditches us for these swabbies.
1974		(con. 1940s) E. Thompson Tattoo (1977) 163: Poor little swabbie.
1986		W.D. Ehrhart Passing Time (1988) 54: The girls got a percentage of every drink the sailors bought, and those swabbies bought a lot of drinks.
1999		N. Stephenson Cryptonomicon 775: ‘What’s the Department of the Navy going to think of that, sir?’ ‘I have no intention of letting the swabbies know I’ve found you.’.
2000		T. Udo Vatican Bloodbath 85–6: You choking on a swabby’s fucken pink torpedo whilst being simultaneously shafted fucken senseless by a fucken beaner.
2011		‘Jack Tunney’ Cutman [ebook] This here’s private parking, swabbie.
2011		D.R. Pollock Devil All the Time 14: [H]e hadn’t met a single swabby who could hold his liquor.