Business, Legal & Accounting Glossary

Definition: Theory

What is the dictionary definition of Theory?

Dictionary Definition

  1. obsolete Mental conception; reflection, consideration.
  2. 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.
  3. uncountable The underlying principles or methods of a given technical skill, art etc., as opposed to its practice.

Also defined as:

  • A supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.
  • An idea used to account for a situation or justify a course of action.
  • Mathematics A collection of propositions to illustrate the principles of a subject.

Full Definition of Theory

A set of assumptions, propositions, or accepted facts that attempts to provide a plausible or rational explanation of cause-and-effect (causal) relationships among a group of the observed phenomenon. The word “Theory” originates from the Greek word thorós, which means “a spectator”.

The word’s origin stresses the fact that all theories are mental models of the perceived reality.

Examples of Theory in a sentence

In theory, things can only get better; however, in practice, they may actually become a lot worse.

Synonyms For Theory

hypothesis, idea, assumption, opinion, philosophy

Cite Term

To help you cite our definitions in your bibliography, here is the proper citation layout for the three major formatting styles, with all of the relevant information filled in.

Page URL
Modern Language Association (MLA):
Theory. Payroll & Accounting Heaven Ltd. October 25, 2021
Chicago Manual of Style (CMS):
Theory. Payroll & Accounting Heaven Ltd. (accessed: October 25, 2021).
American Psychological Association (APA):
Theory. Retrieved October 25, 2021, from website:

Definition Sources

Definitions for Theory are sourced/syndicated and enhanced from:

  • A Dictionary of Economics (Oxford Quick Reference)
  • Oxford Dictionary Of Accounting
  • Oxford Dictionary Of Business & Management

This glossary post was last updated: 6th January, 2020 | 95 Views.