dilatation vs distention

dilatation

noun
  • Prolixity; diffuse discourse. 

  • The act of dilating; expansion; an enlarging on all sides; the state of being dilated 

  • A dilation or enlargement of a canal or other organ. 

distention

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