aft vs rearward

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. 

rearward

adj
  • Toward the back or rear of something. 

adv
  • Toward the back or rear of something. 

noun
  • The last troop; the rear of an army; a rear guard. 

  • The part that comes last or is situated in the rear; conclusion, wind-up. 

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