Definitions
1.NounThe eighth letter of the Modern Greek alphabet, ninth in Old Greek: Θ, θ.
2.NounThe measure of an angle.
3.NounPitch angle; the angle between an aircraft's longitudinal axis and the horizontal plane.
4.NounThe sensitivity of the value of a derivative with respect to time; the "time decay".
5.NounDesignating 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.NounThe voiceless dental fricative represented by θ.