Noun

(philosophy) An abstract archetype of a given thing, compared to which real-life examples are seen as imperfect approximations; pure essence, as opposed to actual examples.

* {{quote-magazine, date=2013-10-19, volume=409, issue=8858, magazine=(The Economist)

, title= Trouble at the lab , passage=The idea that the same experiments always get the same results, no matter who performs them, is one of the cornerstones of science’s claim to objective truth. If a systematic campaign of replication does not lead to the same results, then either the original research is flawed (as the replicators claim) or the replications are (as many of the original researchers on priming contend). Either way, something is awry.}}

(obsolete) The conception of someone or something as representing a perfect example; an ideal.

(obsolete) The form or shape of something; a quintessential aspect or characteristic.

*, II.6:

The remembrance whereof (which yet I beare deepely imprinted in my minde) representing me her visage and Idea so lively and so naturally, doth in some sort reconcile me unto her.

An image of an object that is formed in the mind or recalled by the memory.

More generally, any result of mental activity; a thought, a notion; a way of thinking.

*

, title=(The Celebrity), chapter=3 , passage=Now all this was very fine, but not at all in keeping with the Celebrity's character as I had come to conceive it. The idea that adulation ever cloyed on him was ludicrous in itself. In fact I thought the whole story fishy, and came very near to saying so.}}

* 1952 , (Alfred Whitney Griswold)

Ideas won't go to jail.

A conception in the mind of something to be done; a plan for doing something, an (l).

* , chapter=3

, title= Mr. Pratt's Patients , passage=My hopes wa'n't disappointed. I never saw clams thicker than they was along them inshore flats. I filled my dreener in no time, and then it come to me that 'twouldn't be a bad idee to get a lot more, take 'em with me to Wellmouth, and peddle 'em out. Clams was fairly scarce over that side of the bay and ought to fetch a fair price.}}

* {{quote-magazine, date=2013-06-01, volume=407, issue=8838, page=71, magazine=(The Economist)

, title= End of the peer show , passage=Finance is seldom romantic. But the idea of peer-to-peer lending comes close. This is an industry that brings together individual savers and lenders on online platforms. Those that want to borrow are matched with those that want to lend.}}

A vague or fanciful (l); a feeling or hunch; an impression.

(music) A musical theme or melodic subject.

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