Entry 1 sense Webster, 1913 Suicidal /so͞oˌ-əs-īd'-əl/ · Su·i·ci·dal · IPA /ˌsu.əˈsaɪ.dəl/ 01 a. Partaking of, or of the nature of, the crime or suicide. 1. Partaking of, or of the nature of, the crime or suicide.