Green’s Dictionary of Slang

(US) pertaining to illegal Mexican immigrants.

1954		J. Steinbeck Sweet Thursday (1955) 21: How did he get in the wet-back business?
1972		C. Bukowski Erections, Ejaculations etc. 358: You go to town, get drunk, catch a cheap blowjob from a wetback Mexican senorita.
1981		J. Wambaugh Glitter Dome (1982) 121: Put him in a manure bag and send him to those wetback farmworkers to spread on all that boycotted lettuce.
2004		J. Ellroy ‘Hollywood Fuck Pad’ in Destination: Morgue! (2004) 209: He owned two wetback garment mills.
2010		J. Franco Palo Alto (2011) 21: The other guys worked up this chant. They were saying, ‘Wetback attack’.
2019		S.M. Jones Lives Laid Away [ebook] ‘Tell this wetback shit stain to shut up’.
2021		J. Ellroy Widespread Panic 87: A wetback waiter wafted into view.