MP3 (acronym) Type: noun, acronym Pronunciation: /M-P-3/ Also spelled or known as: M.P.3 What does MP3 mean and stand for? MPEG Audio Layer-3; An audio file format. Example sentence: “Send me the mp3 to spin at the club tonight.” MP3 in songs: “I should download her audio on MP3” – Eminem, The Real Slim Shady. […]