Word family noun forgetfulness adjective forgetful forgettable ≠ unforgettable verb forget adverb forgetfully unforgettably
From Longman Dictionary of Contemporary Englishunforgettableun‧for‧get‧ta‧ble /ˌʌnfəˈɡetəbəl◂ $ -fər-/ adjective REMEMBERan unforgettable experience, sight etc affects you so strongly that you will never forget it, especially because it is particularly good or beautiful → memorable A visit to Morocco is a truly unforgettable experience. —unforgettably adverbExamples from the Corpus
unforgettable• To everyone who has ever heard a fairy tale, the image of being lost in a deep, dark wood is unforgettable.• How the boys could play football from 8-9 am I don't know - it was totally unforgettable!• a series of unforgettable characters• But the last 16 minutes blotted out all the blundering and turned this into an unforgettable classic.• It was an unforgettable evening.• The trip had been an unforgettable experience for both of them.• Nevertheless, Adam feels a moment of unforgettable happiness and assumes that Hetty knows what he is feeling.• His vocal range is amazing, and used to convey unforgettable melodies that sound a lot simpler than they are.• one of the movie's unforgettable moments• It was a pitiful, unforgettable sight, and I sincerely hoped I would never have to witness anything like that again.• That unforgettable summer, Sussler heard Agnes de Mille lecture authoritatively on dance. 