Definition of "thesis"

Senses relating to logic, rhetoric, etc.

1. (rhetoric) A proposition or statement supported by arguments.  examples

2. (by extension) A lengthy essay written to establish the validity of a thesis (sense 1.1), especially one submitted in order to complete the requirements for a non-doctoral degree in the US and a doctoral degree in the UK; a dissertation.  quotations  examples

   Quotations

   • I told them of the grave, becoming, and ſublime deportment they ſhould aſſume upon this myſtical occaſion, and read them two homilies and a theſis of my own compoſing, in order to prepare them.

     1766, [Oliver Goldsmith], “The Conclusion”, in The Vicar of Wakefield: […], volume II, Salisbury, Wiltshire: […] B. Collins, for F[rancis] Newbery, […]; reprinted London: Elliot Stock, 1885, pages 218–219

3. (mathematics, computer science) A conjecture, especially one too vague to be formally stated or verified but useful as a working convention.  examples

4. (logic) An affirmation, or distinction from a supposition or hypothesis.  examples

5. (philosophy) In the dialectical method of Georg Wilhelm Friedrich Hegel: the initial stage of reasoning where a formal statement of a point is developed; this is followed by antithesis and synthesis.  examples

Senses relating to music and prosody.

1. (music, prosody, originally) The action of lowering the hand or bringing down the foot when indicating a rhythm; hence, an accented part of a measure of music or verse indicated by this action; an ictus, a stress.  examples

2. (music, prosody, with a reversal of meaning) A depression of the voice when pronouncing a syllables of a word; hence, the unstressed part of the metrical foot of a verse upon which such a depression falls, or an unaccented musical note.  examples