wetback

[ wet-bak ]
/ ˈwɛtˌbæk /

noun Slang: Extremely Disparaging and Offensive.

a contemptuous term used to refer to a Mexican laborer who enters the U.S. illegally, as by wading the Rio Grande.

Origin of wetback

An Americanism dating back to 1945–50; wet + back1

British Dictionary definitions for wetback

wetback
/ (ˈwɛtˌbæk) /

noun

US informal, offensive a Mexican labourer who enters the US illegally

Word Origin for wetback

C20: illegal immigrants would swim across the Rio Grande river to reach the US