dreadnought

something or someone that is unusually large and powerful poor gas mileage did little to stem the popularity of that dreadnought of the roadways: the SUV Synonyms behemoth, blockbuster, colossus, dinosaur, giant, elephant, Goliath, jumbo, leviathan, mammoth, mastodon, monster, titan, whale, whopperRelated Words amazon, giantess; bulk, hulk; heavyweight; juggernaut, steamrollerNear Antonyms lightweight, weakling, wimp, wisp; nonentity, twerp, whippersnapperAntonyms diminutive, dwarf, half-pint, midget, mite, peewee, pygmy (also pigmy), runt, shrimp