caudal vs rearmost

caudal

adj
  • Pertaining to the tail or posterior or hind part of a body. 

  • Toward the tail end (hind end) of the body; in bipeds such as humans, this direction corresponds to inferior. 

noun
  • A caudal vertebra. 

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 caudal and rearmost occurred in a corpus of books? (source: Google Ngram Viewer )