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theta Syllabification: the·ta
Pronunciation: /ˈTHātə/ /ˈTHē-/

Definition of theta in English:


1The eighth letter of the Greek alphabet (Θ, θ), transliterated as ‘th.’.
Example sentences
  • English borrowed the digraph th from Latin, where it served to transliterate Greek theta; th superseded other symbols for the dental fricative following the advent of printing.
  • Look lower down the alphabet - theta perhaps, or even upsilon.
  • With these basic relationships in mind, let's now take a closer look at time value and the rate of time-value decay (represented by theta, from the Greek alphabet).
1.1 (Theta) [followed by Latin genitive] Astronomy The eighth star in a constellation: Theta Draconis
More example sentences
  • It is 4.8° SSW of Theta Aurigae.
  • Some of Ara's stars are very distant: both Gamma Arae and Theta Arae lie more than 1,000 light years away, but both of these stars are brilliant supergiants, and so are clearly visible to the naked eye of an observer on Earth.
1.2 [as modifier] Chemistry Denoting a temperature at which a polymer solution behaves ideally as regards its osmotic pressure.
Example sentences
  • For a given star polymer the theta temperature can be lower or higher than that of the corresponding linear polymer depending on the number and length of its branches.
  • We use equations derived from the blob theory to calculate the blob size and the theta temperature of star polymers.
1.3 [as modifier] Denoting electrical activity observed in the brain under certain conditions, consisting of oscillations having a frequency of 4 to 7 hertz: theta rhythm
More example sentences
  • Abnormalities in electroencephalograph theta and delta activity, visual evoked potentials, and brainstem evoked potentials have been reported in children exposed to molds.
  • The abnormalities have included right hemisphere dominance and excessively slow frequency EEG theta activity.
  • During the transition from a waking state to a drowsy-sleep state, the participant might lose the dominant beta/alpha frequencies and display theta activity.


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1 (θ) Temperature (especially in degrees Celsius).
1.1 (θ) A plane angle.
1.2 (θ) A polar coordinate. Often coupled with phi.

Words that rhyme with theta

Akita, Anita, arboreta, beater, beta, Bhagavadgita, cheater, cheetah, Demeter, Dieter, dolce vita, eater, eta, Evita, excreta, fetor, granita, greeter, heater, Juanita, litre (US liter), Lolita, maltreater, margarita, meter, metre, Peta, praetor (US pretor), repeater, Rita, saltpetre (US saltpeter), secretor, Senhorita, señorita, Sita, skeeter, teeter, terra incognita, treater, tweeter, ureter, veleta, zeta

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