›[C or U]a formal statement of ideas that are suggested to explain a fact or event, or how something works: He has four theories to explain organizational change and development.economic/political theoryEconomic theory says that there is little connection between the euro's value against the dollar or the yen and the success of monetary union itself.a theory of sthIn this article the authors develop a theory of high-performing organizations.
›[C or U]a formal statement of the rules or principles on which an activity or a subject of study is based: management/organization theoryThis case study has important implications for management theorythe theory and practice of running a department
›[C]a statement of an opinion or an explanation of an idea that is believed to be true, but might be wrong: The theory is that staff react better to praise than to criticism. People will buy the product if you put it in the right place - well, that's the theory anyway.
in theory›if something is possible in theory, it should be possible, but often it does not happen in that way: In theory, you can be up and trading in a just a day.Employing fewer people sounds great in theory, but how's it going to work out in practice?