astronomical(also astronomic), Brobdingnagian, bumper, colossal, cosmic(also cosmical), cyclopean, elephantine, enormous, galactic, gargantuan, gigantesque, gigantic, grand, herculean, heroic(also heroical), Himalayan, huge, humongous(also humungous), immense, jumbo, king-size(or king-sized), leviathan, mammoth, massive, mega, mighty, monster, monstrous, monumental, mountainous, oceanic, pharaonic, planetary, prodigious, super, super-duper, supersize, supersized, titanic, tremendous, vast, vasty, walloping, whacking, whopping

big, bulky, considerable, extensive, good, goodly, great, gross, handsome, hefty, hulking, largish, major, outsize(also outsized), overgrown, oversize(or oversized), sizable(or sizeable), substantial, tidy, voluminousaugust, formidable, grandiose, imposing, lofty, majesticcavernous, monolithic, overwhelming, staggering, stupendous, toweringboundless, immeasurable, infinite

bantam, bitty, diminutive, infinitesimal, Lilliputian, little bitty, micro, microminiature, microscopic(also microscopical), midget, miniature, minuscule, minute, pocket, pygmy, teensy, teensy-weensy, teeny, teeny-weeny, tiny, wee

little, mini, petite, pint-size(or pint-sized), puny, small, smallish, undersized(also undersize)dinky, dwarfish, half-pint