difference

Etymology

From Middle English difference, from Old French difference, from Latin differentia (“difference”), from differēns (“different”), present participle of differre. Doublet of differentia. Morphologically differ + -ence.

noun

1. (uncountable) The quality of being different.
   You need to learn to be more tolerant of difference.
2. (countable) A characteristic of something that makes it different from something else.
   There are three differences between these two pictures.
   But poverty’s scourge is fiercest below $1.25 (the average of the 15 poorest countries’ own poverty lines, measured in 2005 dollars and adjusted for differences in purchasing power): people below that level live lives that are poor, nasty, brutish and short. 2013-06-01, “Towards the end of poverty”, in The Economist, volume 407, number 8838, page 11
3. (countable) A disagreement or argument.
   We have our little differences, but we are firm friends.
   Away therefore went I with the constable, leaving the old warden and the young constable to compose their difference as they could. 1714, Thomas Ellwood, The History of the Life of Thomas Ellwood: written by his own hand
4. (countable, uncountable) Significant change in or effect on a situation or state.
   It just won't make much difference to me.
   It just won't make much of a difference to anyone.
   As she did so Fanny put down her book , stood up and stretched her arms, and at once Jessamy noticed a difference. It was the same Fanny but not the Fanny who climbed trees and tore her frock playing in the garden. It was as though a young lady film had settled over her, neatening her unruly hair, which was tied back with a large black bow, and primly composing her small mouth. 1967, Barbara Sleigh, Jessamy, Sevenoaks, Kent: Bloomsbury, published 1993, page 105
5. (countable) The result of a subtraction; sometimes the absolute value of this result.
   The difference between 3 and 21 is 18.
6. (obsolete) Choice; preference.
7. (heraldry) An addition to a coat of arms to distinguish two people's bearings which would otherwise be the same. See augmentation and cadency.
8. (logic) The quality or attribute which is added to those of the genus to constitute a species; a differentia.
9. (logic circuits) A Boolean operation which is true when the two input variables are different but is otherwise false; the XOR operation ( scriptstyle A◌̅B+◌̅AB).
10. (relational algebra) The set of elements that are in one set but not another ( scriptstyle A◌̅B).

verb

1. (obsolete, transitive) To distinguish or differentiate.
   […] and souls, like in the mass, but differenced in themselves, with special gifts, duties and joys […] 1901 [1839], Philip James Bailey, Festus: A Poem, London: George Routledge & Sons, page 10
   In the Calais Roll the arms of William de Warren […] are differenced by the addition of a canton said to be that of Fitzalan […] 1904, Arthur Charles Fox-Davies, The Art of Heraldry: An Encyclopædia of Armory, London: T.C. & E.C. Jack, page 344