hypothesis

American  

[hahy-poth-uh-sis, hi-] / haɪˈpɒθ ə sɪs, hɪ- /

noun

• hypotheses
  plural

1. 

   a proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation working hypothesis or accepted as highly probable in the light of established facts.

2. a proposition assumed as a premise in an argument.

3. the antecedent of a conditional proposition.

4. a mere assumption or guess.

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hypothesis British  

/ haɪˈpɒθɪsɪs /

noun

1. a suggested explanation for a group of facts or phenomena, either accepted as a basis for further verification ( working hypothesis ) or accepted as likely to be true Compare theory

2. an assumption used in an argument without its being endorsed; a supposition

3. an unproved theory; a conjecture

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hypothesis Scientific  

/ hī-pŏth′ĭ-sĭs /

• hypotheses
  plural

1. A statement that explains or makes generalizations about a set of facts or principles, usually forming a basis for possible experiments to confirm its viability.

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hypothesis Cultural  

1. plur. hypotheses (heye-poth-uh-seez) In science, a statement of a possible explanation for some natural phenomenon. A hypothesis is tested by drawing conclusions from it; if observation and experimentation show a conclusion to be false, the hypothesis must be false. (See scientific method and theory.)

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Usage

What is a hypothesis? In science, a hypothesis is a statement or proposition that attempts to explain phenomena or facts. Hypotheses are often tested to see if they are accurate. Crafting a useful hypothesis is one of the early steps in the scientific method, which is central to every field of scientific experimentation. A useful scientific hypothesis is based on current, accepted scientific knowledge and is testable. Outside of science, the word hypothesis is often used more loosely to mean a guess or prediction.

Synonym Usage

See theory.

Other Word Forms

Derived Forms

• counterhypothesis
  noun
• hypothesist
  noun
• subhypothesis
  noun

Inflected Forms

Nouns

• hypotheses
  plural

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Etymology

Origin of hypothesis

First recorded in 1590–1600, hypothesis is from the Greek word hypóthesis “basis, supposition”; see hypo-, thesis

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Explanation

In science, a hypothesis is an idea or explanation that you then test through study and experimentation. Outside science, a theory or guess can also be called a hypothesis. A hypothesis is something more than a wild guess but less than a well-established theory. In science, a hypothesis needs to go through a lot of testing before it gets labeled a theory. In the non-scientific world, the word is used a lot more loosely. A detective might have a hypothesis about a crime, and a mother might have a hypothesis about who spilled juice on the rug. Anyone who uses the word hypothesis is making a guess.

Example Sentences

See Examples For:

hypothesis hypotheses

The hypothesis holds that some problems are so hard that computers can solve them only by trying nearly every possible answer.

From Barron's ● Oct. 30, 2026

If the models went from being stumped by long division to cracking the quasi-Riemann hypothesis in five years, how will the next five years play out?

From The Wall Street Journal ● Oct. 24, 2026

The central message of the adaptive aging hypothesis is that growing older may involve more than a gradual reduction in cognitive abilities.

From Science Daily ● Oct. 20, 2026

A new paper looking at the chemical reactions between water and disintegrating plastic offers a potential hypothesis for how microplastics might make us sick.

From Los Angeles Times ● Oct. 17, 2026

Because of the unknown factor, STSs must develop a reasonable and responsible hypothesis before engaging in spatial teleportation.

From "The First State of Being" by Erin Entrada Kelly

"When we get the sample back, we'll be able to look in detail at its chemistry and its mineral composition - and the two hypotheses will produce very distinct results," said Sara Russell.

From BBC ● Oct. 18, 2026

It offers disciplined methods for testing hypotheses, challenging assumptions and correcting errors.

From The Wall Street Journal ● Sep. 13, 2026

The 15 partnerships with global firms it has disclosed have an aggregate headline contract value exceeding $11 billion and suggest it can convert hypotheses into development assets and commercial transactions at scale.

From The Wall Street Journal ● Sep. 3, 2026

But there are several hypotheses, says Dr Alex Gofton, a tick expert who led a recent study into the allergy.

From BBC ● Jul. 20, 2026

After all, it’s not the outlandishness of its conclusions that makes something a pseudoscience: lucky guesses, serendipity, bizarre hypotheses, and even an initial gullibility all play a role in science as well.

From "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos

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Related Words

• assumption
• axiom
• conclusion
• conjecture
• explanation
• guess
• inference
• interpretation
• premise
• proposition
• rationale
• supposition
• theorem
• thesis

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