M3 (slang) Type: noun, slang Pronunciation: /em-three/ What does M3 mean? A Motorsport edition from BMW’s 3 Series. M3 Synonyms: Bimmer, Beamer Example sentence: “I was on the PCH in my M3.” M3 in songs: “Dick many hoes on the pimpy mode M3 note that’s that new Hat to the back in that black new coupe” – […]