humped vs sigmoid

humped

adj
  • Having a hump or humps, or, in combination, a hump or humps of the specified number or type. 

sigmoid

adj
  • Relating to the sigmoid colon. 

  • Exhibiting logistic growth; having a graph that accelerates until it reaches a carrying capacity. 

  • Curved in two directions, like the letter "S", or the Greek ς (sigma); having a serpentine shape. 

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