from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The eighth letter of the Greek alphabet. See Table at alphabet.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. the name for the eighth letter οf the Modern Greek alphabet, ninth in Old Greek.
- n. The measure of an angle.
from the GNU version of the Collaborative International Dictionary of English
- n. 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.
from The Century Dictionary and Cyclopedia
- n. As used in formulæ of mathematics and engineering, theta (θ) usually denotes:
- n. the entropy, or thermodynamic function or factor by which the absolute temperature is to be multiplied to indicate an amount of heat energy.
- n. The angle, in angular measure, or at the center, through which a radius vector has swept from a zero position, or through which a line has swept in a rotation.
- n. A letter of the Greek alphabet corresponding to the English th in thin, etc.
- n. A sort of complication of an exponential function, being expressed by a series from n =—∞ to n = + ∞ of terms the logarithm of each of which is na + 2 na. A theta function of several variables, x1, x2, … xn, is
Σexp. ( φ+ Σmxn xn), where φis a quadratic function of the constants m1, m2, … mn.
- n. A function which occurs in probabilities, and is expressed by the integral fe—tdt.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the 8th letter of the Greek alphabet
Greek thēta, of Phoenician origin; akin to Hebrew ṭêt, teth.(American Heritage® Dictionary of the English Language, Fourth Edition)
From the Ancient Greek θῆτα (thēta). (Wiktionary)