adj. 25B6; adjective
a big building : LARGE, sizeable, substantial, great, huge, immense, enormous, extensive, colossal, massive, mammoth, vast, tremendous, gigantic, giant, monumental, mighty, gargantuan, elephantine, titanic, mountainous, Brobdingnagian; towering, tall, high, lofty; outsize, oversized; goodly; capacious, voluminous, spacious; king-size(d), man-size, family-size(d), economy-size(d); informal jumbo, whopping, thumping, bumper, mega, humongous, monster, astronomical, almighty, dirty great, socking great; Brit. informal whacking, ginormous; formal commodious.
a big man : WELL BUILT, sturdy, brawny, burly, broad-shouldered, muscular, muscly, rugged, lusty, Herculean, bulky, hulking, strapping, thickset, stocky, solid, hefty; tall, huge, gigantic; fat, stout, portly, plump, fleshy, paunchy, corpulent, obese; informal hunky, beefy, husky; poetic/literary thewy, stark.
my big brother : GROWN-UP, adult, mature, grown; elder, older.
a big decision : IMPORTANT, significant, major, momentous, weighty, consequential, far-reaching, key, vital, critical, crucial.
(informal) a big man in the government : POWERFUL, important, prominent, influential, high-powered, leading; N. Amer. major-league.
(informal) he has big plans : AMBITIOUS, far-reaching, grandiose, on a grand scale.
she's got a big heart : GENEROUS, kind, kindly, caring, compassionate, loving.
(informal) African bands are big in Britain : POPULAR, successful, in demand, sought-after, all the rage; informal hot, in, cool, trendy, now, hip; Brit. informal, dated all the go.
small, minor, modest.
25A0; too big for one's boots (informal) CONCEITED, full of oneself, swollen-headed, cocky, arrogant, cocksure, above oneself, self-important; vain, self-satisfied, pleased with oneself, smug, complacent; informal big-headed; poetic/literary vainglorious.