Entry 1 sense Webster, 1913 Obliteration /əb-lĭtˌ-ẽr-āsh'-ən/ · Ob·lit·er·a·tion · IPA /əblˌɪtərˈeɪʃən/ 01 n. The act of obliterating, or the state of being obliterated; extinction. 1. The act of obliterating, or the state of being obliterated; extinction.