Noun

(obsolete) Mental conception; reflection, consideration.

* 1646 , (Thomas Browne), Pseudodoxia Epidemica , VII.19:

As they encrease the hatred of vice in some, so doe they enlarge the theory of wickednesse in all.

(sciences) A coherent statement or set of ideas that explains observed facts or phenomena, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc.

* 2002 , Duncan Steel, The Guardian , 23 May 2002:

It was only when Einstein's theory' of relativity was published in 1915 that physicists could show that Mercury's "anomaly" was actually because Newton's gravitational ' theory was incomplete.

* 2003 , (Bill Bryson), A Short History of Nearly Everything , BCA, p. 118:

The world would need additional decades [...] before the Big Bang would begin to move from interesting idea to established theory .

* 2009 , (Richard Dawkins), The Greatest Show On Earth: The Evidence for Evolution , Bantam, p. 10:

Scientists and creationists are understanding the word "theory'" in two very different senses. Evolution is a '''theory''' in the same sense as the heliocentric '''theory'''. In neither case should the word "only" be used, as in "only a ' theory ".

* {{quote-magazine, date=2012-01

, author=Michael Riordan , title=Tackling Infinity , volume=100, issue=1, page=86 , magazine= citation , passage=Some of the most beautiful and thus appealing physical theories', including quantum electrodynamics and quantum gravity, have been dogged for decades by infinities that erupt when theorists try to prod their calculations into new domains. Getting rid of these nagging infinities has probably occupied far more effort than was spent in originating the ' theories .}}

(uncountable) The underlying principles or methods of a given technical skill, art etc., as opposed to its practice.

* 1990 , Tony Bennett, Outside Literature , p. 139:

Does this mean, then, that there can be no such thing as a theory of literature?

* 1998 , Elizabeth Souritz, The Great History of Russian Ballet :

Lopukhov wrote a number of books and articles on ballet theory , as well as his memoirs.

(mathematics) A field of study attempting to exhaustively describe a particular class of constructs.

Knot theory classifies the mappings of a circle into 3-space.

A hypothesis or conjecture.

* 1999 , Wes DeMott, Vapors :

It's just a theory I have, and I wonder if women would agree. But don't men say a lot about themselves when a short-skirted woman slides out of a car or chair?

* 2003 , Sean Coughlan, The Guardian , 21 Jun 2003:

The theory is that by stripping costs to the bone, they are able to offer ludicrously low fares.

(countable, logic) A set of axioms together with all statements derivable from them. Equivalently, a formal language plus a set of axioms (from which can then be derived theorems).

A theory is consistent if it has a model.

Noun

(en-noun)

(label) A great attention and concern from someone or something; intellectual curiosity.

*

, title=(The Celebrity), chapter=10 , passage=The skipper Mr. Cooke had hired at Far Harbor was a God-fearing man with a luke warm interest in his new billet and employer, and had only been prevailed upon to take charge of the yacht after the offer of an emolument equal to half a year's sea pay of an ensign in the navy.}}

* , chapter=1

, title= Mr. Pratt's Patients, chapter=1 , passage=Thinks I to myself, “Sol, you're run off your course again. This is a rich man's summer ‘cottage’ and if you don't look out there's likely to be some nice, lively dog taking an interest in your underpinning.”}}

(label) Attention that is given to or received from someone or something.

* , chapter=7

, title= The Mirror and the Lamp , passage=[…] St.?Bede's at this period of its history was perhaps the poorest and most miserable parish in the East End of London. Close-packed, crushed by the buttressed height of the railway viaduct, rendered airless by huge walls of factories, it at once banished lively interest from a stranger's mind and left only a dull oppression of the spirit.}}

* {{quote-magazine, date=2013-08-10, volume=408, issue=8848, magazine=(The Economist)

, title= Standing orders , passage=Over the past few years, however, interest has waxed again. A series of epidemiological studies, none big enough to be probative, but all pointing in the same direction, persuaded Emma Wilmot of the University of Leicester, in Britain, to carry out a meta-analysis. This is a technique that combines diverse studies in a statistically meaningful way.}}

(label) A business or amorous link or involvement.

* {{quote-magazine, date=2013-06-21, author= Chico Harlan

, volume=189, issue=2, page=30, magazine=(The Guardian Weekly) , title= Japan pockets the subsidy , passage=Across Japan, technology companies and private investors are racing to install devices that until recently they had little interest in: solar panels. Massive solar parks are popping up as part of a rapid build-up that one developer likened to an "explosion."}}

(label) Something one is interested in.

Injury, or compensation for injury; damages.

*, II.12:

How can this infinite beauty, power and goodnes admit any correspondencie or similitude with a thing so base and abject as we are, without extreme interest and manifest derogation from his divine greatnesse?

The persons interested in any particular business or measure, taken collectively.