S: (adj) powerful (having great power or force or potency or effect) "the most powerful government in western Europe"; "his powerful arms"; "a powerful bomb"; "the horse's powerful kick"; "powerful drugs"; "a powerful argument"
S: (adj) potent, strong, stiff (having a strong physiological or chemical effect) "a potent toxin"; "potent liquor"; "a potent cup of tea"; "a stiff drink"
W: (adj) impotent [Opposed to: potent] (lacking power or ability) "Technology without morality is barbarous; morality without technology is impotent"- Freeman J.Dyson; "felt impotent rage"