Entry 1 sense Webster, 1913 Homicidal /hämˌ-əs-īd'-əl/ · Hom·i·ci·dal · IPA /hˌɑməsˈaɪdəl/ 01 a. Pertaining to homicide; tending to homicide; murderous; as, a homicidal maniac. 1. Pertaining to homicide; tending to homicide; murderous; as, a homicidal maniac.