UNALTERABLE Meaning of UNALTERABLE in English un ‧ al ‧ ter ‧ a ‧ ble AC /ʌnˈɔːlt ə rəb ə l $ -ˈɒːl-/ BrE AmE adjective formal not possible to change:an unalterable fact —unalterably adverb Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012