the·​sis | \ˈthē-səs, British especially for sense 3 ˈthe-sis\
plural theses\ ˈthē-​ˌsēz \

Definition of thesis 

1 : a dissertation embodying results of original research and especially substantiating a specific view especially : one written by a candidate for an academic degree

2a : a proposition to be proved or one advanced without proof : hypothesis

b : a position or proposition that a person (such as a candidate for scholastic honors) advances and offers to maintain by argument

3a(1) : the unstressed part of a poetic foot especially in accentual verse

(2) : the longer part of a poetic foot especially in quantitative verse

b : the accented part of a musical measure : downbeat — compare arsis

4 : the first and least adequate stage of dialectic — compare synthesis

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Did You Know?

In high school, college, or graduate school, students often have to write a thesis on a topic in their major field of study. In many fields, a final thesis is the biggest challenge involved in getting a master's degree, and the same is true for students studying for a Ph.D. (a Ph.D. thesis is often called a dissertation). But a thesis may also be an idea; so in the course of the paper the student may put forth several theses (notice the plural form) and attempt to prove them.

Examples of thesis in a Sentence

She wrote her thesis on Renaissance Nativity scenes. a master's thesis on the effects of global warming New evidence supports his thesis. We disagreed with the basic thesis of the report. The book's central thesis is that propaganda influences the masses in important ways.
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Recent Examples on the Web

The DePaul graduate described his senior thesis as two orphans unknowingly asking the devil to adopt them with an oujia board. Nathaniel Cline,, "Former area sprinter showcases 'All Kids Go To Hell' animation at the Cleveland International Film Festival 2018," 5 Apr. 2018 Later, during the 2017 mayoral campaign, surrogates for Nirenberg’s opponents derided Nirenberg for selecting the topic for his thesis and for his job after working for the public policy center — managing the Trinity University jazz radio station. Josh Baugh, San Antonio Express-News, "Nirenberg knew immediately that he’d eventually marry Erika Prosper," 17 Mar. 2018 Amy Schumer wrote her college thesis on the male gaze. Eliza Berman, Time, "Amy Schumer Knows She’ll Make More Mistakes. But She’s Ready to Listen and Learn," 12 Apr. 2018 Her senior thesis is focused on how the diffusion equation is used in chemical engineering. Kate Murphy,, "She's been offered $2.3M in scholarships to Ph.D. programs. She's not old enough to vote.," 29 Mar. 2018 This thesis of the memo, compiled by House Intelligence Committee Chairman Rep. David Nunes, R-Calif., is an idealistic vision of the FISA process. Danny Cevallos, NBC News, "Nunes memo fails to make legal case against the FBI," 3 Feb. 2018 Wilson instead wrote her master’s thesis on an algebraic topic, a branch of math built on the relationships between numbers. Jasper Scherer, San Antonio Express-News, "‘Comfortable in her own skin’: Mary Wilson bids to become the first lesbian Baptist pastor in Congress," 15 May 2018 Kirschling, a rawboned young man from Wisconsin, had written a master’s thesis at Columbia about long-term productivity decline in New York City’s mass transit. William Finnegan, The New Yorker, "Can Andy Byford Save the Subways?," 2 July 2018 In one moment, Young would provide dense detail relating to Jackie Robinson breaking the color line, a topic of his senior thesis at Princeton. Tom Krasovic,, "MLB gets it right with hire of ex-Padres pitcher Chris Young," 11 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thesis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of thesis

14th century, in the meaning defined at sense 3a(1)

History and Etymology for thesis

in sense 3, Middle English, lowering of the voice, from Late Latin & Greek; Late Latin, from Greek, downbeat, more important part of a foot, literally, act of laying down; in other senses, Latin, from Greek, literally, act of laying down, from tithenai to put, lay down — more at do

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Statistics for thesis

Last Updated

9 Nov 2018

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Time Traveler for thesis

The first known use of thesis was in the 14th century

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More Definitions for thesis



English Language Learners Definition of thesis

: a long piece of writing on a particular subject that is done to earn a degree at a university

: a statement that someone wants to discuss or prove


the·​sis | \ˈthē-səs \
plural theses\ -​ˌsēz \

Kids Definition of thesis

1 : a statement that a person wants to discuss or prove

2 : an essay presenting results of original research

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