Definition of "theta" in Englisch

noun

1. The eighth letter of the Modern Greek alphabet, ninth in Old Greek: Θ, θ.

2. (mathematics) The measure of an angle.

3. (aviation, by extension) Pitch angle; the angle between an aircraft's longitudinal axis and the horizontal plane.

4. (finance) The sensitivity of the value of a derivative with respect to time; the "time decay".

5. (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).

6. (phonology) The voiceless dental fricative represented by θ.