gargantuan UK /ɡɑːˈɡæn.t͡ʃu.ən/US /ɡɑɹˈɡæn.t͡ʃu.ən/ adjective2 •Huge; immense; tremendous.Boxy and unrefined, the Hummer embodied an outlandishly masculine aesthetic that seemed to almost revel in its gargantuan fuel consumption. — 2022 •(no longer used) Of the giant Gargantua or his appetite. formsmore Gargantuan · more gargantuan · most Gargantuan · most gargantuan