follow Dictionary.com

Are yams and sweet potatoes the same?

theory

[thee-uh-ree, theer-ee] /ˈθi ə ri, ˈθɪər i/
noun, plural theories.
1.
a coherent group of tested general propositions, commonly regarded as correct, that can be used as principles of explanation and prediction for a class of phenomena:
Einstein's theory of relativity.
Synonyms: principle, law, doctrine.
2.
a proposed explanation whose status is still conjectural and subject to experimentation, in contrast to well-established propositions that are regarded as reporting matters of actual fact.
3.
Mathematics. a body of principles, theorems, or the like, belonging to one subject:
number theory.
4.
the branch of a science or art that deals with its principles or methods, as distinguished from its practice:
music theory.
5.
a particular conception or view of something to be done or of the method of doing it; a system of rules or principles:
conflicting theories of how children best learn to read.
6.
contemplation or speculation:
the theory that there is life on other planets.
7.
guess or conjecture:
My theory is that he never stops to think words have consequences.
Idioms
8.
in theory, ideally; hypothetically:
In theory, mapping the human genome may lead to thousands of cures.
Origin
1590-1600
1590-1600; < Late Latin theōria < Greek theōría a viewing, contemplating, equivalent to theōr(eîn) to view + -ia -y3
Can be confused
hypothesis, law, theory (see synonym study at the current entry)
Synonym Study
1, 2. In technical or scientific use, Theory, principle, and law represent established, evidence-based explanations accounting for currently known facts or phenomena or for historically verified experience: the theory of relativity, the germ theory of disease, the law of supply and demand, the principle of conservation of energy. Often the word law is used in reference to scientific facts that can be reduced to a mathematical formula: Newton's laws of motion. In these contexts the terms theory and law often appear in well-established, fixed phrases and are not interchangeable. In both technical and nontechnical contexts, theory can also be synonymous with hypothesis, a conjecture put forth as a possible explanation of phenomena or relations, serving as a basis for thoughtful discussion and subsequent collection of data or engagement in scientific experimentation in order to rule out alternative explanations and reach the truth. In these contexts of early speculation, the words theory and hypothesis are often substitutable for one another: Remember, this idea is only a theory/hypothesis; Pasteur's experiments helped prove the theory/hypothesis that germs cause disease. Obviously, certain theories that start out as hypothetical eventually receive enough supportive data and scientific findings to become established, verified explanations. Although they retain the term theory in their names, they have evolved from mere conjecture to scientifically accepted fact.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for theory
  • Barely a decade ago scientists who study how planets form had to base their theory on a single example-our solar system.
  • But that theory lacks legs, according to a new study.
  • But one theory is that they used maquettes, or small models, made to cast shadows in abstract shapes.
  • It's fine to talk in theory, but freezing does work to keep the jeans from smelling gamey.
  • As per these studies, the theory of memory reconsolidation is unproven.
  • But as support for some vast conspiracy theory, this is simply pathetic.
  • The theory was put to the test the following day, when the ladder saved him from another dark plummet into ice.
  • And so, that theory is tested experimentally and written up.
  • Now, new research seems to confirm the theory that they rafted there.
  • That's all driven by theory and my previously published papers on this topic.
British Dictionary definitions for theory

theory

/ˈθɪərɪ/
noun (pl) -ries
1.
a system of rules, procedures, and assumptions used to produce a result
2.
abstract knowledge or reasoning
3.
a speculative or conjectural view or idea: I have a theory about that
4.
an ideal or hypothetical situation (esp in the phrase in theory)
5.
a set of hypotheses related by logical or mathematical arguments to explain and predict a wide variety of connected phenomena in general terms: the theory of relativity
6.
a nontechnical name for hypothesis (sense 1)
Word Origin
C16: from Late Latin theōria, from Greek: a sight, from theōrein to gaze upon
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for theory
n.

1590s, "conception, mental scheme," from Late Latin theoria (Jerome), from Greek theoria "contemplation, speculation, a looking at, things looked at," from theorein "to consider, speculate, look at," from theoros "spectator," from thea "a view" + horan "to see" (see warrant (n.)). Sense of "principles or methods of a science or art (rather than its practice)" is first recorded 1610s. That of "an explanation based on observation and reasoning" is from 1630s.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
theory in Medicine

theory the·o·ry (thē'ə-rē, thēr'ē)
n.

  1. A systematically organized body of knowledge applicable in a relatively wide variety of circumstances, especially a system of assumptions, accepted principles, and rules of procedure devised to analyze, predict, or otherwise explain the nature or behavior of a specified set of phenomena.

  2. Abstract reasoning; speculation.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
theory in Science
theory
  (thē'ə-rē, thîr'ē)   
A set of statements or principles devised to explain a group of facts or phenomena. Most theories that are accepted by scientists have been repeatedly tested by experiments and can be used to make predictions about natural phenomena. See Note at hypothesis.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
theory in Culture

theory definition


In science, an explanation or model that covers a substantial group of occurrences in nature and has been confirmed by a substantial number of experiments and observations. A theory is more general and better verified than a hypothesis. (See Big Bang theory, evolution, and relativity.)

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source
theory in Technology


The consensus, idea, plan, story, or set of rules that is currently being used to inform a behaviour. This usage is a generalisation and (deliberate) abuse of the technical meaning. "What's the theory on fixing this TECO loss?" "What's the theory on dinner tonight?" ("Chinatown, I guess.") "What's the current theory on letting lusers on during the day?" "The theory behind this change is to fix the following well-known screw...."
(1994-12-14)

The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
Cite This Source

Word of the Day

Difficulty index for theory

All English speakers likely know this word

Word Value for theory

12
10
Scrabble Words With Friends

Quotes with theory

Nearby words for theory