noun

theta

THEE-tuh

Theta (noun) means a letter of the Greek alphabet (Θ, θ), also used in mathematics and science to represent an angle or variable. Example: “In the equation, theta represents the angle of rotation.”

noun

A letter of the Greek alphabet (Θ, θ), also used in mathematics and science to represent an angle or variable.

"In the equation, theta represents the angle of rotation."

In finance, a measure of how quickly an option's value decreases as it approaches its expiration date.

"Traders watch theta closely as an option nears expiry."

How to use theta

Learner’s notes

In plain EnglishA Greek letter often used as a symbol for an angle in maths and physics, or "time decay" in finance.

Common pairings

theta angle theta decay

Word forms

thetas plural, Thetas plural

Study it as flashcards or scroll it in Flow — saved to your collection.

Test yourself on “theta” A quick quiz — meaning, synonyms & usage →

Fill the gap

Can you complete this real example?

In the equation, _____ represents the angle of rotation.

Etymology

From Greek theta, the eighth letter of the modern Greek alphabet.

Origin: Greek

Rhymes for theta

eta beta zeta feta geta meta Greta Sveta Gaeta Geeta taffeta

See all rhymes for theta →

Frequently asked questions

What does “theta” mean?

The word “theta” means a letter of the Greek alphabet (Θ, θ), also used in mathematics and science to represent an angle or variable. In plain terms, a Greek letter often used as a symbol for an angle in maths and physics, or "time decay" in finance.

How do you pronounce “theta”?

“Theta” is pronounced THEE-tuh (/ˈθeɪtə/ in IPA).

How do you use “theta” in a sentence?

Here is “theta” used in a sentence: “In the equation, theta represents the angle of rotation.”

What part of speech is “theta”?

“Theta” is a noun.

Where does the word “theta” come from?

The word “theta” comes from Greek. From Greek theta, the eighth letter of the modern Greek alphabet.

How many meanings does “theta” have?

“Theta” has 2 distinct senses listed in this dictionary. The most common is: a letter of the Greek alphabet (Θ, θ), also used in mathematics and science to represent an angle or variable.