Synonyms for “hefty”

adjective

1. =  big, strong, massive, strapping, robust, muscular, burly, husky (informal), hulking, beefy (informal), brawny • She was quite a hefty woman.
   opposites: little, small, minute, short, tiny, thin, narrow, slight, slim, insignificant, diminutive, ineffectual, inconsequential, pocket-sized, scanty, infinitesimal
2. =  forceful, heavy, powerful, vigorous (slang) • Lambert gave him a hefty shove to send him on his way.
   opposites: gentle, soft, weak, mild, frail, feeble, weedy (informal), wimpish or wimpy (informal)
3. =  heavy, large, massive, substantial, tremendous, awkward, ample, bulky, colossal, cumbersome, weighty, unwieldy, ponderous • The gritty foursome took turns shouldering the hefty load every five minutes.
   opposites: light
4. =  large, massive, substantial, excessive, inflated, sizeable, astronomical (informal), extortionate • A long-distance romance followed with hefty phone bills.