theta

[ they-tuh, thee- ]

/ ˈθeɪ tə, ˈθi- /

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noun

the eighth letter of the Greek alphabet (Θ, θ).

the consonant sound represented by this letter.

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Origin of theta

1595–1605; <Greek thêta<Semitic See teth

Words nearby theta

Sun Also Rises, The, Suppliants, The, Swan Lake, The, The Swiss Family Robinson, The Symposium, theta, tail wagging the dog, the, Tale of Genji, The, talk of the town, the, Taming of the Shrew, The, theta rhythm

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use theta in a sentence

Eta waves aside, rats running in VR also boosted their theta waves compared to those running in the real world.
How Virtual Reality Unveiled a Unique Brain Wave That Could Boost Learning|Shelly Fan|July 6, 2021|Singularity Hub
Similar to previous studies, as the rats ran in both the VR and the real-world track, the team saw theta waves in the hippocampus.
How Virtual Reality Unveiled a Unique Brain Wave That Could Boost Learning|Shelly Fan|July 6, 2021|Singularity Hub
As vice president of Theta, I was tasked with figuring out how to get members more involved.
Frat Culture's Woman Problem|Samantha Wishman|April 22, 2011|DAILY BEAST
In Scientology parlance, good news is theta news; entheta is the opposite.
Is Scientology's Wall Cracking?|Kim Masters|June 28, 2009|DAILY BEAST

The Gothic alphabet, in fact, as used in this country, had a Theta for expressing in one letter our present t and h conjoined.
The Book-Hunter|John Hill Burton
The Theta Gammas wrote her down as material for a quaint little, quiet little dig,—not of sorority interest.
Stanford Stories|Charles K. Field
We'll go back to 29, and put in sine squared theta minus one equal to z sub four.
Spacehounds of IPC|Edward Elmer Smith
In order to make any solution at all possible you have assumed cosine squared theta negligible.
Spacehounds of IPC|Edward Elmer Smith
He maintained, however, that he had noticed Theta Cancri as well as the two planets, but without recording its position.
The Story of the Heavens|Robert Stawell Ball

British Dictionary definitions for theta

theta

/ (ˈθiːtə) /

noun

the eighth letter of the Greek alphabet (Θ, θ), a consonant, transliterated as th

the lower-case form of this letter used in phonetic transcription to represent the voiceless dental fricative th as in thick, bothCompare edh

Word Origin for theta

C17: from Greek, of Semitic origin; compare Hebrew tēth

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for theta (1 of 2)

The Greek letter theta. Entries beginning with this character are alphabetized under theta.

Medical definitions for theta (2 of 2)

theta

[ thā′tə, thē′- ]

The eighth letter of the Greek alphabet.