firm vs not extreme

firm

adj
  • Durable, rigid (material state) 

  • Fixed (in opinion). 

  • Insistent upon something, not accepting dissent. 

  • Steadfast, secure, solid (in position) 

noun
  • A criminal gang, especially based around football hooliganism. 

  • A business partnership; the name under which it trades. 

  • A business enterprise, however organized. 

verb
  • To become firm; stabilise. 

  • To make firm or strong; fix securely. 

  • To improve after decline. 

  • To make compact or resistant to pressure; solidify. 

  • To shorten (of betting odds). 

  • To select (a higher education institution) as one's preferred choice, so as to enrol automatically if one's grades match the conditional offer. 

not extreme

How often have the words firm and not extreme occurred in a corpus of books? (source: Google Ngram Viewer )