thesis
n. countablen. the main idea or argument in a piece of writing, like an essay. It's the central point that the writer tries to prove with evidence.
n. a central proposition or argument advanced and maintained by a writer or speaker. In academic contexts, it refers to the main claim of an essay or a long research paper submitted for a university degree.
The essay's thesis is very clear.
The central thesis of his book is that technology has fundamentally changed social relationships.
While the author's overarching thesis about economic determinism is compelling, several of the supporting historical examples feel underdeveloped and fail to substantiate the claim fully.
From Late Middle English thesis (“lowering of the voice”) and also borrowed directly from its etymon Latin thesis (“proposition, thesis; lowering of the voice”), from Ancient Greek θέσῐς (thésĭs, “arrangement, placement, setting; conclusion, position, thesis; lowering of the voice”), from τῐ́θημῐ (tĭ́thēmĭ, “to place, put, set; to put down in writing; to consider as, regard”) (ultimately from Proto-Indo-European *dʰeh₁- (“to do; to place, put”)) + -σῐς (-sĭs, suffix forming abstract nouns or nouns of action, process, or result). The English word is a doublet of deed. Sense 1.1 (“proposition or statement supported by arguments”) is adopted from antithesis. Sense 1.4 (“initial stage of reasoning”) was first used by the German philosopher Johann Gottlieb Fichte (1762–1814), and later applied to the dialectical method of his countryman, the philosopher Georg Wilhelm Friedrich Hegel (1770–1831). The plural form theses is borrowed from Latin thesēs, from Ancient Greek θέσεις (théseis).
The plural form is 'theses', which follows a Greek pattern.
He wrote two thesis.He wrote two theses.The plural of 'thesis' is 'theses', not 'thesises'. This irregular plural comes from Greek.