Thesis

noun, plural theses
[thee-seez] /ˈθi siz/ (Show IPA)
1.
a proposition stated or put forward for consideration, especially one to be discussed and proved or to be maintained against objections:
He vigorously defended his thesis on the causes of war.
2.
a subject for a composition or essay.
3.
a dissertation on a particular subject in which one has done original research, as one presented by a candidate for a diploma or degree.
4.
Music. the downward stroke in conducting; downbeat.
Compare arsis (def 1).
5.
Prosody.

a part of a metrical foot that does not bear the ictus or stress.
(less commonly) the part of a metrical foot that bears the ictus.
Compare arsis (def 2).

6.
Philosophy. See under Hegelian dialectic.
Hegelian dialectic
noun
1.
an interpretive method, originally used to relate specific entities or events to the absolute idea, in which some assertible proposition (thesis) is necessarily opposed by an equally assertible and apparently contradictory proposition (antithesis) the mutual contradiction being reconciled on a higher level of truth by a third proposition (synthesis)
noun (pl) -ses (-siːz)
1.
a dissertation resulting from original research, esp when submitted by a candidate for a degree or diploma
2.
a doctrine maintained or promoted in argument
3.
a subject for a discussion or essay
4.
an unproved statement, esp one put forward as a premise in an argument
5.
(music) the downbeat of a bar, as indicated in conducting
6.
(in classical prosody) the syllable or part of a metrical foot not receiving the ictus Compare arsis
7.
(philosophy) the first stage in the Hegelian dialectic, that is challenged by the antithesis
Hegelian dialectic
/hɪˈɡeɪlɪan, heɪˈɡiː-/
noun
1.
(philosophy) an interpretive method in which the contradiction between a proposition (thesis) and its antithesis is resolved at a higher level of truth (synthesis)

thesis definition

The central idea in a piece of writing, sometimes contained in a topic sentence.