So exceedingly large or extensive as to suggest a giant or mammoth:
— A gigantic redwood.
— Gigantic disappointment.

synonym: mammoth.

Roget 159: strong, mighty, vigorous, forcible, hard, adamantine, stout, robust, sturdy, hardy, powerful, potent, puissant, valid.    resistless, irresistible, invincible, proof against, impregnable, unconquerable, indomitable, dominating, inextinguishable, unquenchable; incontestable; more than a match for; overpowering, overwhelming; all powerful, all sufficient; sovereign.    able-bodied; athletic; Herculean, Cyclopean, Atlantean^†; muscular, brawny, wiry, well-knit, broad-shouldered, sinewy, strapping, stalwart, gigantic.    manly, man-like, manful; masculine, male, virile.    unweakened^†, unallayed, unwithered^†, unshaken, unworn, unexhausted^†; in full force, in full swing; in the plenitude of power.    stubborn, thick-ribbed, made of iron, deep-rooted; strong as a lion, strong as a horse, strong as an ox, strong as brandy; sound as a roach; in fine feather, in high feather; built like a brick shithouse; like a giant refreshed.    ... show more

Roget 192: large, big; great etc. (in quantity) 31; considerable, bulky, voluminous, ample, massive, massy; capacious, comprehensive; spacious etc. 180; mighty, towering, fine, magnificent.    corpulent, stout, fat, obese, plump, squab, full, lusty, strapping, bouncing; portly, burly, well-fed, full-grown; corn fed, gram fed; stalwart, brawny, fleshy; goodly; in good case, in good condition; in condition; chopping, jolly; chub faced, chubby faced.    lubberly, hulky, unwieldy, lumpish, gaunt, spanking, whacking, whopping, walloping, thumping, thundering, hulking; overgrown; puffy etc. (swollen) 194.    huge, immense, enormous, mighty; vast, vasty; amplitudinous, stupendous; monster, monstrous, humongous, monumental; elephantine, jumbo, mammoth; gigantic, gigantean, giant, giant like, titanic; prodigious, colossal, Cyclopean, Brobdingnagian, Bunyanesque, Herculean, Gargantuan; infinite etc. 105.    large as life; plump as a dumpling, plump as a partridge; fat as a pig, fat as a quail, fat as butter, fat as brawn, fat as bacon.    immeasurable, unfathomable, unplumbed; inconceivable, unimaginable, unheard-of.    of cosmic proportions; of epic proportions, the mother of all, teh granddaddy of all.    ... show more

Roget 206: high, elevated, eminent, exalted, lofty, tall; gigantic etc. (big) 192; Patagonian; towering, beetling, soaring, hanging (gardens); elevated etc. 307; upper; highest etc. (topmost) 210; high reaching, insessorial^†, perching.    upland, moorland; hilly, knobby [U.S.]; mountainous, alpine, subalpine, heaven kissing; cloudtopt^†, cloudcapt^†, cloudtouching^†; aerial.    overhanging etc. v.; incumbent, overlying, superincumbent^†, supernatant, superimposed; prominent etc. v. 250.    tall as a maypole, tall as a poplar, tall as a steeple, lanky etc. (thin) 203.    ... show more

Polish: gargantuiczny, kolosalny, gigantyczny