convex vs incurvate

convex

adj
  • Curved or bowed outward like the outside of a bowl, circle, or sphere. 

  • arranged such that for any two points in the set, a straight line between the two points is contained within the set. 

  • having no internal angles greater than 180 degrees. 

  • having an epigraph that is a convex set. 

noun
  • A playing card made convex for use in cheating. 

  • A small convex mirror used to cheat by observing other players' cards. 

  • Any convex body or surface. 

incurvate

adj
  • Curved; bent; crooked. 

  • bending inwards. 

verb
  • to have a curved or bent shape; to bend or curve inwards. 

  • To bend (especially inwards); to give a curved shape to. 

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