initial vs rearmost

initial

verb
  • To sign one's initial(s), as an abbreviated signature. 

adj
  • Spatially first, placed at the beginning, in the first position; especially said of the first letter of a word. 

  • Chronologically first, early; of or pertaining to the beginning, cause or origin. 

noun
  • A distinguished initial letter of a chapter or section of a document. 

  • onset, part of a syllable that precedes the syllable nucleus in phonetics and phonology. 

  • The first letter of a word or a name. 

  • In plural, the first letter of each word of a person's full name considered as a unit. 

rearmost

adj
  • Furthest to the rear. 

  • The rearmost member of the strike team walked backward to guard them from a surprise attack from behind. 

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