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 ($\backslash scriptstyle\; A\; \backslash overline\; B$).

Noun

(en noun)

A political upheaval in a government or nation state characterized by great change.

The removal and replacement of a government.

Rotation: the turning of an object around an axis.

* 1912 , P. M. Heldt, The Gasoline Automobile: Its Design and Construction, Volume II: Transmission, Running Gear and Control , The Horseless Age Co. (1913), page 147:

The ratio between the speeds of revolution of wheel and disc is substantially equal to the reciprocal of the ratio between the diameter of the wheel and the diameter of the mean contact circle on the disc.

A rotation: one complete turn of an object during rotation.

* 1864 , D. M. Warren, The Common-School Geography , Revised Edition, H. Cowperthwait & Co., page 6:

The Earth has two motions: a daily revolution (or turning around) upon its axis , and a yearly course around the sun.

* 1878 , George Fleming, A Text-Book of Veterinary Obstetrics , Baillière, Tindall, & Cox, page 123:

Numerous cases are recorded which incontestibly prove that during pregnancy, the uterus perform a half or even a complete revolution , on itself, producing torsion of the cervix

In the case of celestial bodies - the traversal of one body through an orbit around another body.

A sudden, vast change in a situation, a discipline, or the way of thinking and behaving.