rounded vs sigmoid

rounded

adj
  • Made into a circle or sphere. 

  • Complete or balanced. 

  • Pronounced with the lips drawn together. 

  • Ending in a broad arch. 

  • Describing a number that has been changed to its nearest desired value. 

sigmoid

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

  • Relating to the sigmoid colon. 

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

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