influential UK /ɪnflʊˈɛnʃəl/US /ˌɪnfluˈɛnʃəl/adjective 1noun 1forms 3 adjective1 •Having or exerting influence.John Lennon was a very influential person in music, as well as in politics, fashion and general culture.Jane was very influential in getting the motion passed. noun1 •A person who has influence formsinfluentials · more influential · most influential