colossal

enormous, immense, huge, vast, gigantic, colossal, mammoth mean exceedingly large. enormous and immense both suggest an exceeding of all ordinary bounds in size or amount or degree, but enormous often adds an implication of abnormality or monstrousness.

• • an enormous expense
• • an immense shopping mall

huge commonly suggests an immensity of bulk or amount.

• • incurred a huge debt

vast usually suggests immensity of extent.

• • the vast Russian steppes

gigantic stresses the contrast with the size of others of the same kind.

• • a gigantic sports stadium

colossal applies especially to a human creation of stupendous or incredible dimensions.

• • a colossal statue of Lincoln

mammoth suggests both hugeness and ponderousness of bulk.

• • a mammoth boulder