unforgettable◼◼◼(very difficult or impossible to forget) adjective [UK: ˌʌn.fə.ˈɡe.təb.l̩] [US: ˌʌn.fər.ˈɡe.təb.l̩]Yesterday's party was an unforgettable one. = La fête d'hier en a été une inoubliable.
immortal◼◻◻(never to be forgotten) adjective [UK: ɪ.ˈmɔːt.l̩] [US: ˌɪ.ˈmɔːr.tl̩]