Gigantic
来自Big Physics
early 17th century (in the sense ‘like or suited to a giant’): from Latin gigas, gigant- (see giant) + -ic.
wiktionary
From Ancient Greek γιγαντικός(gigantikós), ultimately from γίγας(gígas, “giant”). According to the Poly-Olbion project coined by Michael Drayton in 1612.
etymonline
gigantic (adj.)
1610s, "pertaining to giants," from Latin gigant- stem of gigas "giant" (see giant) + -ic. Replaced earlier gigantine (c. 1600), gigantical (c. 1600), giantlike (1570s). The Latin adjective was giganteus. Of material or immaterial things, actions, etc., "of extraordinary sine or proportions," by 1797.