noun hy·poth·e·sis \ hī-ˈpä-thə-səs \
Updated on: 11 Apr 2018

Definition of hypothesis

plural hypotheses play \hī-ˈpä-thə-ˌsēz\
1 a : an assumption or concession made for the sake of argument
b : an interpretation of a practical situation or condition taken as the ground for action
2 : a tentative assumption made in order to draw out and test its logical or empirical consequences
3 : the antecedent clause of a conditional statement

Examples of hypothesis in a Sentence

  1. In contrast to Bingham's hypothesis that Machu Picchu was the birthplace of the first Inca and the hearth area of the Inca civilization, current scholars believe that the city was built as a country estate … —Roger BalmFocus On GeographySpring 2004
  2. Campus veterans marvel at all the poolside apartments that have sprung up since Georgia popped the income cap off its merit awards. Professors are testing their hypothesis that instead of increasing college enrollment, the state's $1.7 billion scholarship program has been a blessing for the automobile industry—since so many families roll the savings into buying new cars. —Greg WinterNew York Times31 Oct. 2002
  3. Isaac Newton initially argued against a parabolic orbit for the … comet of 1680, preferring the hypothesis of two independent comets, one for the inbound and one for the outbound leg. However, Newton later showed that the orbit of the comet could indeed be fit by a parabola. —Daniel C. Boice and Walter Huebner"Physics and Chemistry of Comets," in Encyclopedia of the Solar System Paul R. Weissman et al., editors1999
  4. As stated, our working hypothesis suggests a straightforward way to look for evidence that would confirm or disconfirm it: can you predict what is omitted and what is included in alphabetic representations? —Timothy Shopen and Joseph M. WilliamsStandards and Dialects in English1980
  5. Other chemists rejected his hypothesis.

  6. Their hypothesis is that watching excessive amounts of television reduces a person's ability to concentrate.

  7. The results of the experiment did not support his hypothesis.

Recent Examples of hypothesis from the Web

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

Origin and Etymology of hypothesis

Greek, from hypotithenai to put under, suppose, from hypo- + tithenai to put — more at do

Synonym Discussion of hypothesis

hypothesis, theory, law mean a formula derived by inference from scientific data that explains a principle operating in nature. hypothesis implies insufficient evidence to provide more than a tentative explanation.
    • a hypothesis explaining the extinction of the dinosaurs
theory implies a greater range of evidence and greater likelihood of truth.
    • the theory of evolution
law implies a statement of order and relation in nature that has been found to be invariable under the same conditions.
    • the law of gravitation

HYPOTHESIS Defined for English Language Learners


Definition of hypothesis for English Language Learners

  • : an idea or theory that is not proven but that leads to further study or discussion

HYPOTHESIS Defined for Kids


noun hy·poth·e·sis \ hī-ˈpä-thə-səs \

Definition of hypothesis for Students

plural hypotheses \-ə-ˌsēz\
: something not proved but assumed to be true for purposes of argument or further study or investigation

Medical Dictionary


noun hy·poth·e·sis \ hī-ˈpäth-ə-səs \

medical Definition of hypothesis

plural hypotheses play \-ˌsēz\
: a proposition tentatively assumed in order to draw out its logical or empirical consequences and test its consistency with facts that are known or may be determined
  • it appears, then, to be a condition of the most genuinely scientific hypothesis that it be…of such a nature as to be either proved or disproved by comparison with observed facts
  • —J. S. Mill

Seen and Heard

What made you want to look up hypothesis? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!


without deliberation, pause, or delay

Get Word of the Day daily email!

Test Your Vocabulary

Odd Habits and Quirks Quiz

  • image1926873504
  • Which of the following best describes an easily irritated person?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!