0 in a way that has such a strong effect that you cannot forget it: --
His descriptions are often unforgettably vivid.
He was unforgettably charming and popular.
It was an unforgettably harrowing video.
Seeing your own words in print is unforgettably satisfying.
She was one of the most unforgettably original figures on the international fashion scene.
His book ends, unforgettably, with the sound of the cathedral bells ringing.