Webster's Revised Unabridged Dictionary · 1913

Presumption

Presumption (?; 215) , noun

[Latin praesumptio: compare French présomption, Old French also presumpcion. See Presume.]

1.
The act of presuming, or believing upon probable evidence; the act of assuming or taking for granted; belief upon incomplete proof.
2.
Ground for presuming; evidence probable, but not conclusive; strong probability; reasonable supposition; as, the presumption is that an event has taken place.
3.
That which is presumed or assumed; that which is supposed or believed to be real or true, on evidence that is probable but not conclusive.
In contradiction to these very plausible presumptions. — De Quincey
4.
The act of venturing beyond due beyond due bounds; an overstepping of the bounds of reverence, respect, or courtesy; forward, overconfident, or arrogant opinion or conduct; presumptuousness; arrogance; effrontery.
Thy son I killed for his presumption. — Shakespeare
I had the presumption to dedicate to you a very unfinished piece. — Dryden
Collocations (3)
Conclusive presumption , See under Conclusive.
Presumption of fact (Law) , an argument of a fact from a fact; an inference as to the existence of one fact not certainly known, from the existence of some other fact known or proved, founded on a previous experience of their connection; supposition of the truth or real existence of something, without direct or positive proof of the fact, but grounded on circumstantial or probable evidence which entitles it to belief. — Burrill
Presumption of law (Law) , a postulate applied in advance to all cases of a particular class; e. g., the presumption of innocence and of regularity of records. Such a presumption is rebuttable or irrebuttable.