censure vs slag off

censure

verb
  • To criticize harshly. 

  • To formally rebuke. 

noun
  • An official reprimand. 

  • Judicial or ecclesiastical sentence or reprimand; condemnatory judgment. 

  • The act of blaming, criticizing, or condemning as wrong; reprehension. 

slag off

verb
  • To talk insultingly to or about someone or something; usually one who is not present. 

  • To purify by melting and removing slag. 

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