heavy in weight.

of more than average weight or thickness

a coat of heavyweight material.

noting or pertaining to a boxer, wrestler, etc., of the heaviest competitive class, esp. a professional boxer weighing more than 175 lb. (79.4 kg).

of or pertaining to the weight class or division of such boxers

a heavyweight bout.

(of a riding horse, esp. a hunter) able to carry up to 205 lb. (93 kg).

designating a person, company, nation, or other entity that is extremely powerful, influential, or important

a team of heavyweight lawyers.

a person of more than average weight.

a heavyweight boxer or wrestler.

a person, company, nation, or other entity that is powerful and influential

a price hike initiated by the heavyweights in the industry.

noun

character , eminence , leader , lion , nabob , notability , notable , personage

adjective

hefty , massive , ponderous , weighty , blue-chip , major , major-league