Origin: 1605–15; < L
gigant- giant +
-ic 
Related forms: gi⋅gan⋅ti⋅cal⋅ly, adverb
gi⋅gan⋅tic⋅ness, noun
Synonyms:
1. enormous, immense, prodigious, herculean, cyclopean, titanic. Gigantic, colossal, mammoth, monstrous are used of whatever is physically or metaphorically of great magnitude. Gigantic refers to the size of a giant, or to size or scope befitting a giant: a gigantic stalk of corn. Colossal refers to the size of a colossus, to anything huge or vast as befitting a hero or god: a colossal victory. Mammoth refers to the size of the animal of that name and is used esp. of anything large and heavy: a mammoth battleship. Monstrous means strikingly unusual or out of the normal in some way, as in size: a monstrous blunder.
Antonyms:
1. tiny.