singularly vs unforgettably

singularly

adv
  • Extremely; remarkably. 

  • In the singular number; in terms of a single thing. 

  • solely; only; uniquely 

  • Strangely; oddly. 

unforgettably

adv
  • In an unforgettable manner; very memorably. 

How often have the words singularly and unforgettably occurred in a corpus of books? (source: Google Ngram Viewer )