1. A position or proposition which a person advances and offers to maintain, or which is actually maintained by argument.
2. Hence, an essay or dissertation written upon specific or definite theme; especially, an essay presented by a candidate for a diploma or degree.
"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, to prepare them." -- Goldsmith.
3. (Logic) An affirmation, or distinction from a supposition or hypothesis.
4. (Mus.) The accented part of the measure, expressed by the downward beat; -- the opposite of arsis.
5. (Pros.) (a) The depression of the voice in pronouncing the syllables of a word. (b) The part of the foot upon which such a depression falls.