the·​ta | \ ˈthā-tə How to pronounce theta (audio) , chiefly British ˈthē-tə \

Definition of theta

1 : the 8th letter of the Greek alphabet — see Alphabet Table

Examples of theta in a Sentence

Recent Examples on the Web But along with rate, there’s also timing: As the rat passes through a place field, the associated place cell fires earlier and earlier with respect to the cycle of the background theta wave. Quanta Magazine, 7 July 2021 Alpha and theta waves, described as those of meditation and relaxed focus, make the ball move away from you. Greg Harris,, 19 Feb. 2021 For example, if an option’s theta is minus 0.20, an investor can expect its premium to decline, or decay, 20 cents a day, if everything else remains constant. Nick Ravo, WSJ, 5 Oct. 2020 The theta cycles seem to be a clear entry point to unraveling how that works. Quanta Magazine, 24 Feb. 2020 The angle — θ, or theta — could have ranged anywhere from zero to 360 degrees, representing degrees of difference between quarks and mirror-image antiquarks. Quanta Magazine, 17 Mar. 2020 Perhaps most tellingly, says Sirigu, the man’s brain began producing stronger theta waves, electrical brain rhythms correlated with consciousness. Michael Price, Science | AAAS, 25 Sep. 2017 The researchers are using a form of rTMS called intermittent theta burst stimulation, in which pulses are delivered in bursts, like machine-gun fire. Meredith Wadman, Science | AAAS, 29 Aug. 2017 Psychologists at Oregon speculated that the surge in theta waves stimulated the production of cells in the white matter. Gretchen Reynolds, New York Times, 18 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'theta.' 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 theta

15th century, in the meaning defined at sense 1

History and Etymology for theta

Middle English, from Latin, from Greek thēta, of Semitic origin; akin to Hebrew ṭēth teth

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Time Traveler for theta

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The first known use of theta was in the 15th century

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Dictionary Entries Near theta

the system


the Tabernacle

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Cite this Entry

“Theta.” Dictionary, Merriam-Webster, Accessed 27 Oct. 2021.

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