ad lib vs unintending

ad lib

adj
  • Extemporaneous, impromptu. 

verb
  • To perform without preparation. 

  • To perform without script. 

  • To perform extemporaneously. 

adv
  • Extemporaneously. 

  • At will. 

  • To whatever extent. 

  • At pleasure. 

unintending

adj
  • unintentional 

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