evaluate vs gradate

evaluate

verb
  • To draw conclusions from examining; to assess. 

  • To compute or determine the value of (an expression). 

  • To return or have a specific value. 

gradate

verb
  • To arrange in order of grades. 

  • To change imperceptibly from one gradation of tone etc. to another. 

  • To bring to a certain strength or grade of concentration. 

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