Definitions of presumption:

• noun:   a kind of discourtesy in the form of an act of presuming

  Example: "His presumption was intolerable"

• noun:   audacious (even arrogant) behavior that you have no right to
• noun:   (law) an inference of the truth of a fact from other facts proved or admitted or judicially noticed
• noun:   an assumption that is taken for granted