Noun

(en noun)

A number of things or persons being in some relation to one another.

* , chapter=5

, title= The Mirror and the Lamp , passage=Then everybody once more knelt, and soon the blessing was pronounced. The choir and the clergy trooped out slowly, […], down the nave to the western door. […] At a seemingly immense distance the surpliced group stopped to say the last prayer.}}

* {{quote-magazine, date=2013-07-19, author=(Peter Wilby)

, volume=189, issue=6, page=30, magazine=(The Guardian Weekly) , title= Finland spreads word on schools , passage=Imagine a country where children do nothing but play until they start compulsory schooling at age seven. Then, without exception, they attend comprehensives until the age of 16. Charging school fees is illegal, and so is sorting pupils into ability groups by streaming or setting.}}

(group theory) A set with an associative binary operation, under which there exists an identity element, and such that each element has an inverse.

(geometry, archaic) An effective divisor on a curve.

A (usually small) group of people who perform music together.

(astronomy) A small number (up to about fifty) of galaxies that are near each other.

(chemistry) A column in the periodic table of chemical elements.

(chemistry) A functional entity consisting of certain atoms whose presence provides a certain property to a molecule, such as the methyl group.

(sociology) A subset of a culture or of a society.

(military) An air force formation.

(geology) A collection of formations or rock strata.

(computing) A number of users with same rights with respect to accession, modification, and execution of files, computers and peripherals.

An element of an espresso machine from which hot water pours into the portafilter.

(music) A number of eighth, sixteenth, etc., notes joined at the stems; sometimes rather indefinitely applied to any ornament made up of a few short notes.

(sports) A set of teams playing each other in the same division, while at the same time not playing teams that belong to other sets in the division.

*

Noun

(uncountable) The quality of being different.

(countable) A characteristic of something that makes it different from something else.

* {{quote-magazine, title=Towards the end of poverty

, date=2013-06-01, volume=407, issue=8838, page=11, magazine=(The Economist) citation , passage=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.}}

(countable) A disagreement or argument.

We have our little differences , but we are firm friends.

* Shakespeare

What was the difference ? It was a contention in public.

* T. Ellwood

Away therefore went I with the constable, leaving the old warden and the young constable to compose their difference as they could.

(countable, uncountable) Significant change in or effect on a situation or state.

* 1908 , (Kenneth Grahame), (The Wind in the Willows)

The line of the horizon was clear and hard against the sky, and in one particular quarter it showed black against a silvery climbing phosphorescence that grew and grew. At last, over the rim of the waiting earth the moon lifted with slow majesty till it swung clear of the horizon and rode off, free of moorings; and once more they began to see surfaces—meadows wide-spread, and quiet gardens, and the river itself from bank to bank, all softly disclosed, all washed clean of mystery and terror, all radiant again as by day, but with a difference that was tremendous.

(countable) The result of a subtraction; sometimes the absolute value of this result.

(obsolete) Choice; preference.

* Spenser

That now be chooseth with vile difference / To be a beast, and lack intelligence.

(heraldry) An addition to a coat of arms to distinguish two people's bearings which would otherwise be the same. See augmentation and cadency.

(logic) The quality or attribute which is added to those of the genus to constitute a species; a differentia.

(logic circuits) A Boolean operation which is TRUE when the two input variables are different but is otherwise FALSE; the XOR operation ($\backslash scriptstyle\; A\; \backslash overline\; B\; +\; \backslash overline\; A\; B$).

(relational algebra) the set of elements that are in one set but not another ($\backslash scriptstyle\; A\; \backslash overline\; B$).