assumption in WordNet English dictionary

1. the act of taking possession of or power over something
   "his assumption of office coincided with the trouble in Cuba"; "the Nazi assumption of power in 1934"; "he acquired all the company's assets for ten million dollars and the assumption of the company's debts"
   assumption  laying claim 
   
2. the act of assuming or taking for granted
   "your assumption that I would agree was unwarranted"
   assumption 
   
3. audacious (even arrogant) behavior that you have no right to
   "he despised them for their presumptuousness"
   presumption  presumptuousness  effrontery  assumption 
   
4. a hypothesis that is taken for granted
   "any society is built upon certain assumptions"
   assumption  supposition  supposal 
   
5. a statement that is assumed to be true and from which a conclusion can be drawn
   "on the assumption that he has been injured we can infer that he will not to play"
   premise  premiss  assumption