aft vs rearmost

aft

adj
  • located at the back of a boat, ship, or airplane 

adv
  • At, near, or towards the stern of a vessel (with the frame of reference within the vessel). 

noun
  • The stern portion of a vessel. 

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