Synonyms: unforgettable
Definition: impossible to forget
Similar words: persistent, haunting
Definition: continually recurring to the mind
Usage: haunting memories; the cathedral organ and the distant voices have a haunting beauty- Claudia Cassidy
Similar words: memorable
Definition: worth remembering
Similar words: red-letter
Definition: memorable for being a special occasion
Usage: on red-letter nights a large gathering greeted the celebrity