constant vs exceptional

constant

adj
  • Firm; solid; not fluid. 

  • Unchanged through time or space; permanent. 

  • Steady in purpose, action, feeling, etc. 

  • Bounded above by a constant. 

  • Consistently recurring over time; persistent. 

noun
  • A quantity that remains at a fixed value throughout a given discussion. 

  • Any property of an experiment, determined numerically, that does not change under given circumstances. 

  • That which is permanent or invariable. 

  • An identifier that is bound to an invariant value; a fixed value given a name to aid in readability of source code. 

exceptional

adj
  • Corresponding to something of lower dimension under a birational correspondence. 

  • Forming an exception; not ordinary; uncommon; rare. 

  • Better than the average; superior due to exception or rarity. 

noun
  • An exception, or something having an exceptional value 

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