rearmost vs ulterior

rearmost

adj
  • Furthest to the rear. 

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

ulterior

adj
  • Situated beyond, or on the farther side. 

  • Being intentionally concealed so as to deceive. 

  • Beyond what is obvious or evident. 

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