extremum vs uttermost

extremum

noun
  • A point, or value, which is a maximum or a minimum. 

uttermost

noun
  • The utmost; the highest or greatest degree; the farthest extent. 

adj
  • Outermost. 

  • Extreme; utmost; of the farthest, greatest, or highest degree. 

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