- mastodon⇄adj. very large; gigantic.
Ex. Stone has brought forth a mastodon volume, ""The Passions of the Mind"" (Atlantic).
(SYN) mammoth. - mastodon⇄mastodon, noun, adjective.
- mastodon⇄noun 1. any one of a group of very large extinct mammals, much like mammoths or present-day elephants.
Ex. Prehistoric relatives of the elephant were the mammoths and mastodons that lived in temperate and frigid climates (A. M. Winchester).