[noun] [C] [plural] theses - a long piece of writing on a particular subject, esp. one that is done for a higher college or university degreeShe is writing her thesis on black holes.a doctoral thesis (= for a PhD)(formal) A thesis is also the main idea, opinion or theory of a person or group, or in a piece of writing or a talk.Their main thesis was that war was inevitable.
THESIS
Meaning of THESIS in English
Cambridge English vocab. Кембриджский английский словарь. 2012