firstly vs foremost

firstly

adv
  • In the first place; before anything else; first. 

foremost

adv
  • First in time. 

  • In front, prominently forward. 

  • Most importantly. 

adj
  • Positioned in front of (all) others in space, most forward. 

  • Coming before (all) others in time. 

  • Closest to the bow. 

  • Of the highest rank or position; of the greatest importance; of the highest priority. 

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