theta
UK /ˈθiːtə/ · US /ˈθeɪtə/ noun
Forms thetas
- noun The eighth letter of the Modern Greek alphabet, ninth in Old Greek: Θ, θ.
- noun (mathematics) The measure of an angle.
- noun (aviation, by extension) Pitch angle; the angle between an aircraft's longitudinal axis and the horizontal plane.
- noun (finance) The sensitivity of the value of a derivative with respect to time; the "time decay".
- noun (biology) Designating a level of brain activity as measured by electroencephalography having a frequency of between four and seven cycles per second (associated with drowsiness in adults).
- noun (phonology) The voiceless dental fricative represented by θ.
- noun (US, colloquial) A member of the Kappa Alpha Theta sorority.
Synonyms
Etymology
Borrowed from Ancient Greek θῆτα (thêta).
Webster’s 1913
- noun A letter of the Greek alphabet corresponding to th in English; --sometimes called the unlucky letter, from being used by the judges on their ballots in passing condemnation on a prisoner, it being the first letter of the Greek qa`natos, death. Theta function (Math.), one of a group of functions used in developing the properties of elliptic functions.
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “theta”, CC BY-SA 4.0. Details