Entry 1 sense Webster, 1913 Disillusionment /dĭsˌ-ĭl-o͞ozh'-ən-mənt/ · Dis·il·lu·sion·ment · IPA /ˌdɪsɪˈluʒənmənt/ 01 n. The act of freeing from an illusion, or the state of being freed therefrom. 1. The act of freeing from an illusion, or the state of being freed therefrom.