gen·too \ˈjen.ˌtü, ̷ ̷ˈ ̷ ̷\noun (-s) Etymology: Portuguese gentio, literally, Gentile, from Late Latin gentilis — more at gentile 1.usually capitalized, archaic: hindu 2.orgentoo penguin: a penguin (Pygoscelis papua) of the subantarctic islands with a slaty gray back and throat, white underparts, and white spots above the eyes and on the back and side of the neck