distended vs gibbous

distended

adj
  • Extended or expanded, as from internal pressure; swollen. 

  • gravid. 

gibbous

adj
  • Characterized by convexity; protuberant. 

  • Humpbacked. 

  • Having more than half (but not the whole) of its disc illuminated. 

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