having or exerting great power or force.

physically strong, as a person

a large, powerful athlete.

producing great physical effects, as a machine or a blow.

potent; efficacious

a powerful drug.

having great effectiveness, as a speech, speaker, description, reason, etc.

having great power, authority, or influence; mighty

a powerful nation.

Chiefly South Midland and Southern U.S. great in number or amount

a powerful lot of money.

adjective

impotent , incapable , ineffective , unable , weak

adjective

able , all-powerful , almighty , authoritarian , authoritative , capable , cogent , commanding , compelling , competent , controlling , convincing , dominant , dynamic , effectual , efficacious , energetic , forceful , forcible , impressive , in control , influential , in the saddle , mighty , omnipotent , overruling , paramount , persuasive , potent , preeminent , prevailing , puissant , robust , ruling , sovereign , stalwart , strapping * , strengthy , sturdy , supreme , telling , upper hand * , vigorous , weighty , wicked * , wieldy , hard , heavy , hefty , dynamical , effective , hard-hitting , strong , consequential , important , armipotent , brawny , dominating , drastic , great , herculean , intense , invincible , leonine , passive , stentorian , stout , supine , versatile