Entry 2 senses Webster, 1913 Criminology /(-n?l"?-j?)/ · Crim·i·nol·o·gy · IPA /krˌɪmɪnˈɑlədʒiː/ 01 n. A treatise on crime or the criminal population. 1. A treatise on crime or the criminal population. 2. The branch of sociology which studies crime and criminals.