raincoat UK /ˈɹeɪnkəʊt/US /ˈɹeɪnkoʊt/ noun2 •A waterproof coat to be worn in the rain; (loosely) any coat or jacket with this purpose. •(slang) A condom.Moe said he'll go first, I said I'll take next / Here, take this raincoat and practice safe sex! — 1993 formsraincoats