J-Lo UK /ˈd͡ʒeɪləʊ/US /ˈd͡ʒeɪloʊ/ noun1 •(informal, slang) Large buttocks, usually attractive ones.Ace gave her an endearing slap on her J-Lo, causing a little jump her on her way out. Juana by all appearances seemed to be fine. — 2010 formsJ-Los