potent adjective. › ​powerful, persuasive, or ​effective: This is the most potent ​headache ​remedy you can get without a ​prescription. Her ​voice has been a potent ​force on ​concert ​stages for more than 30 ​years. potency noun [U] us /ˈpoʊ·tən·si/ › Scientists are ​testing the potency of the new ​drug. noun [U] us /ˈpoʊ·tən·si/.