presumption

Etymology

Borrowed from Middle French presumption, from Old French presumption, from Latin praesumptiō.

noun

1. the act of presuming, or something presumed
   Yet, in contradiction to all these very plausible presumptions, even this remote period teems with its own peculiar and separate instruction. 1832, Thomas De Quincey, "James's History of Charlemagne", Blackwood
2. the belief of something based upon reasonable evidence, or upon something known to be true
   The presumption is that an event has taken place.
   I have here imputed the Continuance of the War to the mutual Indulgence between our General and Allies, wherein they both so well found their Accounts; to the Fears of the Mony-changers, left their Tables should be overthrown; to the Designs of the Whigs, who apprehended the Loss of their Credit and Employments in a Peace; and to those at home, who held their immoderate Engrossments of Power and Favour, by no other Tenure than their own Presumption upon the Necessity of Affairs. 1712, Jonathan Swift, The Conduct of the Allies, p. 33
3. the condition upon which something is presumed
4. (dated) arrogant behaviour; the act of venturing beyond due bounds of reverence or respect
   Thy son I killed for his presumption. 1591, William Shakespeare, Henry VI, Part 3, act V, scene 6
   I had the presumption to Dedicate to your Lordship: A very unfinish'd Piece … 1893, John Dryden, The satires of Decimus Junius Juvenalis translated into English verse, Dedication, p ii
   If I had not persuaded Harriet into liking the man, I could have borne any thing. He might have doubled his presumption to me—but poor Harriet! 1815, Jane Austen, Emma, volume I, chapter 16
5. (law) An inference that a trier of fact is either permitted or required to draw under certain factual circumstances (as prescribed by statute or case law) unless the party against whom the inference is drawn is able to rebut it with admissible, competent evidence.
   The state, in the exercise of its general power to prescribe rules of evidence, may provide that proof of a particular fact, or of several facts taken collectively, shall be prima facie evidence of another fact when there is some rational connection between the fact proved and the ultimate fact presumed. The legislative presumption is invalid when it is entirely arbitrary, or creates an invidious discrimination, or operates to deprive a party of a reasonable opportunity to present the pertinent facts in his defense. Bandini Petroleum Co. v. Superior Court, 284 U.S. 8, 18–19 (1931)