Venn diagram
noun /ˈven daɪəɡræm/
  /ˈven daɪəɡræm/
(mathematics)- a picture showing sets (= groups of things that have a shared quality) as circles that cross over each other, to show which qualities the different sets have in common
enlarge imageWord Originearly 20th cent.: named after John Venn (1834–1923), English logician. 
