unforgettable
adj.so special, beautiful, or shocking that you cannot forget it. You use this to describe a memory that stays in your mind for a long time.
adj.impossible to forget; very memorable. Often used to describe significant personal experiences or striking sensory impressions.
“Our trip to the mountains was truly unforgettable.”
“The singer gave an unforgettable performance that left the entire audience in tears.”
“The sunset over the ancient ruins provided an unforgettable backdrop to the final evening of our journey, etching itself into our collective memory.”
Often follows a linking verb like 'be', 'seem', or 'become'; frequently modified by intensifiers such as 'truly' or 'absolutely'.
From un- + forget + -able or un- + forgettable.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.