discoursing vs rehearsal

discoursing

noun
  • conversation 

rehearsal

noun
  • The act of rehearsing or contriving something; the fact of something's being rehearsed. 

  • A preparatory activity analogous to the rehearsal of a show. 

  • The practicing of something which is to be performed before an audience, usually to test or improve the interaction between several participating people, or to allow technical adjustments with respect to staging to be done. 

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