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


from The American Heritage® Dictionary of the English Language, 4th Edition

[Greek bēta, of Phoenician origin; see byt in Semitic roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek βῆτα (bēta)


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  • The new version plays on Windows, MacOS and Linux, and, while still in beta, is far more stable and robust.

    Boing Boing: July 16, 2006 - July 22, 2006 Archives 2006

  • Antibiotics such as penicillin are called, collectively, beta-lactams, and enzymes that break down these antibiotics and confer drug resistance are called beta-lactamases, which is why the term beta-lactamase may pop up in this blog entry from time to time.

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  • But there's no evidence suggesting that such evolution should be represented by the term beta, even if marketers wanted it to. jkOnTheRun: Apple 24-inch Cinema Display on the way, again

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  • "We have a unique definition of the term beta, but it basically amounts to products meeting very high internal standards," Kovacs said.

    Redmond Channel Partner Online | News 2009

  • But there's no evidence suggesting that such evolution should be represented by the term beta, even if marketers wanted it to. jkOnTheRun: Apple 24-inch Cinema Display on the way, again

    GigaOM 2009

  • I have heard that the beta is available to folks who bought the last Counterstrike game.

    Prepare to Drool 2004

  • It is two drugs in one-what we call a beta-blocker and a diuretic.

    Blue Shoes And Happiness Smith, Alexander McCall 2006

  • There was what he called a beta copy made by the Dr. Phil show.

    CNN Transcript Dec 1, 2005 2005

  • Q&A format as well as moving forth into social search by launching what it calls the beta version of "new Ask. com" site, focusing on its proprietary technology designed for Q&A.

    Search Engine Watch 2010

  • As I've said in my prepared remarks, we're quite proud of the fact that against what we call a beta headwind, we were able to deliver alpha results to our investors, and look forward to talking to you next quarter.

    Nasdaq OMX Group Q3 2010 Earnings Call Transcript -- Seeking Alpha 2010

  • Her father often gives her tactical advice—what climbers call beta—especially after she falls.

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  • Beta is the second letter of the Greek alphabet. Is derived from the Phoenician letter 'Beth' (meaning 'house'). In Ancient Greek the name was spelt Βήτα and the modern English name (beta)is derived from how it was pronounced. In mathematics and physics it is used to talk about beta particles and radition.

    June 23, 2008

  • The nickname of Eratosthenes, for being second best in many fields.

    June 25, 2008

  • The British pronunciation always makes me chuckle. Horribly provincial of me, I know.

    June 25, 2008

  • I'm never sure how to pronounce it.

    Good betta best

    Never let it rest

    Until your good is bayta

    And your beata best!

    June 25, 2008

  • Also (for fanfic):

    n. a beta reader

    v.t. do a beta read of

    July 3, 2008

  • This word is used differently in rock climbing as noted by the Double-Tongued Dictionary:

    in the sport of rock climbing, advice or instruction on the best way to climb a geographic feature.

    April 1, 2009