gibbous vs protrusive

gibbous

adj
  • Characterized by convexity; protuberant. 

  • Humpbacked. 

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

protrusive

adj
  • that protrudes; protruding 

  • rather conspicuous; obtrusive 

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