converb vs verbal noun

converb

noun
  • A non-finite verb form that serves to express adverbial subordination. 

  • A verb with a stressed, separable prefix. 

verbal noun

noun
  • A noun that is morphologically related to a verb and similar to it in meaning; in English, it contrasts with the gerund and the deverbal noun. 

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