perfect vs richen

perfect

verb
  • To make perfect; to improve or hone. 

  • To take an action, usually the filing of a document in the correct venue, that secures a legal right. 

noun
  • A perfect score; the achievement of finishing a stage or task with no mistakes. 

  • A leader of the Cathar movement. 

  • The perfect tense, or a form in that tense. 

adj
  • Fitting its definition precisely. 

  • Having all of its parts in harmony with a common purpose. 

  • Of a number: equal to the sum of its proper divisors. 

  • Of flowers, having both male parts (stamens) and female parts (carpels). 

  • Of a set: equal to its set of limit points, i.e. set A is perfect if A=A'. 

  • Sexually mature and fully differentiated. 

  • Made with equal parts of sweet and dry vermouth. 

  • Excellent and delightful in all respects. 

  • Representing a completed action. 

  • Describing an interval or any compound interval of a unison, octave, or fourths and fifths that are not tritones. 

  • Without fault or mistake; thoroughly skilled or talented. 

richen

verb
  • To become rich or richer; become superior in quality, condition or effectiveness. 

  • To make or render rich or richer. 

  • To gain richness; become heightened or intensified in brilliancy. 

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