Presume  v. (-ming) 1 (often foll. By that) suppose to be true; take for granted. 2 (often foll. By to + infin.) A take the liberty, be impudent enough (presumed to question their authority). B dare, venture (may i presume to ask?). 3 be presumptuous. 4 (foll. By on, upon) take advantage of or make unscrupulous use of (a person's good nature etc.). [latin praesumo]