substantial

1 having great meaning or lasting effect substantial changes to the school dress code that made a lot of people unhappy Synonyms big, consequential, earthshaking, earth-shattering, eventful, historic, major, material, meaningful, momentous, monumental, much, significant, important, tectonic, weightyRelated Words decisive, fatal, fateful, strategic; earnest, grave, heavy, serious, sincere; distinctive, exceptional, impressive, outstanding, prominent, remarkable; valuable, worthwhile, worthy; distinguished, eminent, great, illustrious, noble, notable, noteworthy, outstanding, preeminent, prestigious; famous, notorious, renowned; all-important, central, critical, crucial, essential, key, pivotal, seminal, vitalNear Antonyms paltry, petty, worthless; anonymous, nameless, obscure, uncelebrated, unknownAntonyms inconsequential, inconsiderable, insignificant, little, minor, negligible, slight, small, trifling, trivial, unimportant

2 of a size greater than average of its kind the amount he inherited was quite substantial, so he quit his job and set out to see the world Synonyms big, biggish, boxcar, bulky, considerable, goodly, grand, great, handsome, hefty, hulking, husky, largish, outsize (also outsized), oversize (or oversized), sizable (or sizeable), large, tidy, voluminousRelated Words astronomical (also astronomic), Brobdingnagian, bumper, Bunyanesque, cavernous, colossal, cosmic (also cosmical), cyclopean, elephantine, enormous, galactic, gargantuan, gigantic, gross, hellacious, herculean, heroic (also heroical), Himalayan, huge, humongous (also humungous), immense, jumbo, king-size (or king-sized), leviathan, major, mammoth, massive, monolithic, monstrous, monumental, mountainous, pharaonic, prodigious, staggering, stupendous, super, super-duper, supersized, titanic, tremendous, vast, vasty, walloping, whacking, whopping; excessive, exorbitant, extravagant, extreme, immoderate, inordinate; abundant, ample, appreciable, copious, plentiful; fat, thick; capacious, commodious, roomy, spaciousNear Antonyms diminutive, half-pint, infinitesimal, Lilliputian, little-bitty, microminiature, microscopic (also microscopical), mini, miniature, minuscule, minute, pint-size (or pint-sized), pocket-size (also pocket-sized), pygmy, teensy, teensy-weensy, teeny, teeny-weeny, tiny, wee; petite, slender, slight, slim, thinAntonyms bantam, dinky, dwarf, dwarfish, little, puny, shrimpy, small, smallish, undersized (also undersize)

3 relating to or composed of matter the Land of Oz turned out to be a world of dreams, even less substantial than a rainbow Synonyms concrete, physical, materialRelated Words bodily, carnal, corporal, corporeal, embodied, fleshly; apparent, appreciable, detectable, discernible (also discernable), noticeable, observable, palpable, perceptible, seeable, sensible, tangible, touchable, visible; objective, phenomenal; bulky, heavy, hefty, massive, ponderous, solid, weightyNear Antonyms bodiless, discarnate, disembodied, formless, incorporeal, unbodied; ethereal, insubstantial, unsubstantial; impalpable, imperceptible, insensible, intangible, invisible, unnoticeable; airy, diaphanous, gossamery, tenuous, thin, vaporous, wispish; metaphysical, spiritualAntonyms immaterial, nonmaterial, nonphysical

4 sufficiently large in size, amount, or number to merit attention there's been a substantial increase in attendance at girls' volleyball games ever since the start of their winning streak Synonyms biggish, good, goodly, handsome, healthy, largish, major, respectable, significant, sizable (or sizeable), considerable, substantive, tidyRelated Words big, bulky, hefty, hulking, outsize (also outsized), oversize (or oversized), voluminous; astronomical (also astronomic), bumper, colossal, elephantine, enormous, gigantic, great, herculean, huge, immense, jumbo, king-size (or king-sized), mammoth, massive, monstrous, monumental, prodigious, titanic, tremendous, whoppingNear Antonyms measly, minute, paltry, petty, picayune, picayunish, piddling, puny, trifling, trivial, unimportant; marginal, meager (or meagre), slight; little, small, tiny, undersized (also undersize); bitty, diminutive, miniature, pint-size (or pint-sized), pocket, pocket-size (also pocket-sized), pygmy, smallishAntonyms inconsequential, inconsiderable, insignificant, insubstantial, negligible, nominal