Marvin Share definition Flag to ogle, or stare at the opposite genders body, in an extreme fashion, especially their chest or butt. ESPECIALLY when on a date I went on a first date the other night with a real loser... He didn't look me in the eye all night..He was totally MARVINing my boobs. Marvin by Myndie December 29, 2008 Get the Marvin mug.