Entry 1 sense Webster, 1913 Psychologist /sīk-äl'-əj-əst/ · Psy·chol·o·gist · IPA /ˌsaɪˈkɑl.ə.d͡ʒɪst/ 01 n. One who is versed in, devoted to, psychology. 1. One who is versed in, devoted to, psychology.