Entry 2 senses · 2 variants Webster, 1913 Socialist · So·cial·ist · IPA /ˈsoʊ.ʃə.lɪst/ n. a. 01 n. One who advocates or practices the doctrines of socialism. 1. One who advocates or practices the doctrines of socialism. 02 a. Pertaining to, or of the nature of, socialism. 1. Pertaining to, or of the nature of, socialism.