beta

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The second letter of the Greek alphabet.
• noun The second item in a series or system of classification.
• noun A mathematical measure of the sensitivity of rates of return on a portfolio or a given stock compared with rates of return on the market as a whole. A beta of 1.0 indicates that an asset closely follows the market; a beta greater than 1.0 indicates greater volatility than the market.
• noun Astronomy The second brightest star in a constellation.
• noun Computers The version of a software or hardware product used in a beta test.
• adjective Being the second-ranked individual of one's sex. Used of social animals.
• adjective Being in the second position relative to a designated carbon atom in an organic molecule at which an atom or a group may be substituted.
• adjective Referring to the second of a group of isomers, or molecules of similar origin or properties, determined arbitrarily by those who discover or classify them. Used in combination.
• adjective Computers Of or relating to a beta test or the software or hardware involved in a beta test.

from The Century Dictionary.

• noun The second letter of the Greek alphabet, corresponding to English B or b.
• noun As a classifier in astronomy, chemistry, etc., the second in any series. See alpha, 3.
• noun A genus of dicotyledonous plants belonging to the family Chenopodiaceæ.
• noun In the Fiji Islands, a plant of the ginger family, Zinziber Zerumbet. See awapuhi.
• noun A genus of apetalous plants, natural order Chenopodiaceæ. See beet.

from the GNU version of the Collaborative International Dictionary of English.

• noun The second letter of the Greek alphabet, B, β. See b, and cf. etymology of alphabet.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Identifying a molecular position in an organic chemical compound.
• adjective Designates the second in an order of precedence.
• adjective computing Preliminary; prerelease. Refers to an incomplete version of a product released for initial testing.
• adjective of a person associated with the beta male/female archetype.
• noun The name of the second letter of the Greek alphabet (Β,  β), preceded by alpha (Α,  α) and followed by gamma, (Γ,  γ). In modern Greek it represents the voiced labiodental fricative sound of v found in the English words have and vase.
• noun Used in marking scheme: α, β, γ or α+, α, α-, β etc.
• noun finance Average sensitivity of a security's price to overall securities market prices.
• noun computing The phase of development after alpha testing and before launch, in which software, while not complete, has been released to potential users for testing.
• noun computing A computer program in such phase; a preliminary version.
• noun climbing Information about a route which may aid someone in climbing it.
• noun physics A beta particle or beta ray.
• noun A beta fish, of the genus Betta.
• noun A beta male.
• verb computing To preliminarily release computer software for initial testing prior to final release.
• verb To proofread a text, especially fan fiction.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun beets
• adjective second in order of importance
• noun the 2nd letter of the Greek alphabet
• adjective preliminary or testing stage of a software or hardware product