1.express a supposition;
Let us say that he did not tell the truth
2.expect, believe, or suppose;
I imagine she earned a lot of money with her new novel
3.to believe especially on uncertain or tentative grounds;
Scientists supposed that large dinosaurs lived in swamps
4.take for granted or as a given; suppose beforehand;
I presuppose that you have done your work
5.require as a necessary antecedent or precondition;
This step presupposes two prior ones