em-, emp-, empt- (sump-, -sum-)

1. To accept that something is virtually certain to be correct even though there is no proof of it, on the grounds that it is extremely likely.
2. To behave so inconsiderably, disrespectfully, or overconfidently as to do something without being entitled or qualified to do it; usually used in a negative sense.

To presume means "to consider likely, to expect," or "to think to be a fact": "Since the firm is prosperous and my work has been very good, I presume I will get a raise."

In modern usage, assume and presume are often used for both meanings.

1. The taking upon onself of more than is warranted by one's position, right, or (formerly) ability; forward or over-confident opinion or conduct; arrogance, pride, effrontery, assurance.
2. The assuming or taking of something for granted; also, that which is presumed or assumed to be, or to be true, on probable evidence; a belief deduced from facts or experience; assumption, assumed probability, supposition, expectation.
3. In law, presumption of fact: the inference of a fact not certainly known, from known facts.
4. In law, presumption of law: the assumption of the truth of anything until the contrary is proved or an inference established by the law as universally applicable to certain circumstances.
5. A ground or reason for presuming or believing; presumptive evidence.

1. Giving reasonable grounds for presumption or belief; warranting inference.
2. Based on presumption or inference; presumed, inferred.

By presumption or inference; presumably.

Characterized by presumption in opinion or conduct; unduly confident or bold; arrogant, presuming; forward, impertinent.

In a presumptuous manner; with presumption.

The quality of being presumptuous; groundless self-confidence; over-bold forwardness.

Prompt and sincere.

Motto of Calvin Theological Seminary, Grand Rapids, Michigan, USA.