1. (a.) Of extraordinary size; like a giant\.

2. (a.) Such as a giant might use, make, or cause; immense; tremendous; extraordinarily; as, gigantic deeds; gigantic wickedness.

Antaean Atlantean Briarean Brobdingnagian Cyclopean Gargantuan Herculean Homeric a bit much abandoned abysmal amplitudinous astronomic astronomical awesome big boundless bulky colossal cosmic cyclopean egregious elephantine enormous epic exaggerated excessive exorbitant extensive extravagant extreme fabulous fancy galactic gangling gangly gargantuan giant giantlike gluttonous heroic high huge hulking humongous hyperbolic hypertrophied immeasurable immense immoderate incontinent infinite inordinate intemperate jumbo king-size lank lanky large leggy lengthy long long-legged mammoth massive massy mighty monster monstrous monumental mountainous out of bounds out of sight outrageous outsize overbig overdeveloped overgreat overgrown overlarge overmuch overweening prodigious profound rangy sizable spacious staggering statuesque steep stiff strapping stupendous tall thumping thundering titanic too much towering tremendous unbridled unconscionable undue unreasonable unrestrained vast voluminous walloping weighty whopping