approval vs stricture

approval

noun
  • Something mailed by a seller to a collector to match their stated interests; the collector can approve of or return the item. 

  • An expression granting permission; an indication of agreement with a proposal; an acknowledgement that a person, thing, or event meets requirements. 

  • An expression of favorable acceptance and encouragement; a compliment that also condones. 

stricture

noun
  • The degree of contact, in consonants. 

  • Abnormal narrowing of a canal or duct in the body. 

  • A general state of restrictiveness on behavior, action, or ideology. 

  • A rule restricting behaviour or action. 

  • A sternly critical remark or review. 

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