be·​ta | \ ˈbā-tə How to pronounce beta (audio) , chiefly British ˈbē- \

Definition of beta

 (Entry 1 of 2)

1 : the 2nd letter of the Greek alphabet — see Alphabet Table
3 : a measure of the risk potential of a stock or an investment portfolio expressed as a ratio of the stock's or portfolio's volatility to the volatility of the market as a whole
4 : a nearly complete prototype of a product (such as software) the beta version also : a stage of development in which a product is nearly complete but not yet ready for release released in beta



Definition of beta (Entry 2 of 2)

: second in position in the structure of an organic molecule from a particular group or atom beta substitution often used in combination symbol β

Examples of beta in a Sentence

Noun a program that is currently in beta
Recent Examples on the Web: Noun Bolstering the report from Hits Daily Double, MacRumors found code in the first iOS 14.6 beta which seems to spoil the company’s plans to launch a new tier for its music streaming service. Jacob Siegal, BGR, "Apple might reveal AirPods 3 and a HiFi Apple Music plan soon," 3 May 2021 Prior to launch, the product was beta tested in partnership with The Chicago Lighthouse, Open Style Lab, and Muscular Dystrophy Association. Sarah Midkiff,, "Degree Just Launched The World’s First Deodorant For People With Disabilities," 27 Apr. 2021 Xbox Cloud Gaming is available this week in a limited beta for both the web as well as the Apple iPhone and iPad. Mark Hachman, PCWorld, "Hands on: Xbox Cloud Gaming for the web brings Xbox gaming to your browser," 23 Apr. 2021 My app had a curious tab for Items added way back at the beginning of the beta. Anthony Karcz, Forbes, "iOS 14.5 Starts Losing Features As Apple Rolls Out Public Beta 7," 7 Apr. 2021 For years, Synairgen has been developing a breathable mist of interferon-beta to help severe asthma and chronic obstructive pulmonary disease patients better fight off viral infections. Michael Greshko, National Geographic, "These promising coronavirus treatments are saving lives," 28 Aug. 2020 Starlink’s beta started in December 2020 and has been slowly expanding to match the minimal needs of the network. Christopher Hutton, Washington Examiner, "Elon Musk is making a new move as an internet service provider," 22 Apr. 2021 The iPhone 12 got a new color, and the last iOS 14.5 public beta was just released, with the public version of the new software update set to arrive in a few days. Chris Smith, BGR, "Some of iOS 15’s most exciting new features were revealed by a top leaker," 22 Apr. 2021 When people took meditation breaks, by contrast, the increase in beta activity dropped between meetings. Bruce Rogers, Forbes, "Our Brains Need Breaks From Virtual Meetings," 20 Apr. 2021 Recent Examples on the Web: Adjective The company is already in a beta testing phase and has permission to provide its services in North America. Mike Wehner, BGR, "UFOs spotted over Washington have a very boring explanation," 5 May 2021 Biden's happy to be beta, letting the government work around him and taking credit for what comes. Zachary B. Wolf, CNN, "Biden's superpower will soon be tested," 27 Apr. 2021 Owens informed Apple, which fixed the bug in beta versions of the new Big Sur OS this week. Thomas Brewster, Forbes, "Update Your Mac Now: The ‘Worst Hack In Years’ Hits Apple Computers," 26 Apr. 2021 Chemical exfoliants, on the other hand, are acid-based — think alpha hydroxy acids like glycolic acid, beta hydroxy acids like salicylic acid, and so on. Nicola Dall'asen, Allure, "How to Tell If You're Over-Exfoliating Your Skin," 25 Apr. 2021 Granting that this is a beta experience, there’s definitely room for improvement. Mark Hachman, PCWorld, "Hands on: Xbox Cloud Gaming for the web brings Xbox gaming to your browser," 23 Apr. 2021 There's a revenge-of-the-beta-male vibe in the film's first act, which establishes Hutch as the victim of the castrating world around him. Darren Franich,, "Bob Odenkirk is maybe too convincing as a grim action hero in Nobody: Review," 22 Mar. 2021 The app program is still in beta testing but the company's directory of apps lists three dozen offerings. Aaron Pressman, Fortune, "How Zoom plans to stick around long after the pandemic," 19 Apr. 2021 Spree plans to open it platform in beta testing sometime next week, Sarkis said. Ricardo Torres, Milwaukee Journal Sentinel, "NFTs with Wisconsin connections: Giannis, Tyler Herro and an artist called Beeple who sold a digital collage for $70 million," 16 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'beta.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of beta


14th century, in the meaning defined at sense 1


1862, in the meaning defined above

History and Etymology for beta


Middle English betha, from Latin beta, from Greek bēta, of Semitic origin; akin to Hebrew bēth beth

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Time Traveler for beta

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The first known use of beta was in the 14th century

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Last Updated

8 May 2021

Cite this Entry

“Beta.” Dictionary, Merriam-Webster, Accessed 16 May. 2021.

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English Language Learners Definition of beta

: the second letter of the Greek alphabet
: a version of a product (such as a computer program) that is almost finished and that is used for testing


be·​ta | \ ˈbāt-ə, chiefly British ˈbē-tə \

Medical Definition of beta

 (Entry 1 of 2)

1 : the second letter of the Greek alphabet symbol Β or β
3 : beta wave


variants: or β-

Medical Definition of beta (Entry 2 of 2)

1 : of or relating to one of two or more closely related chemical substances the beta chain of hemoglobin β-yohimbine used somewhat arbitrarily to specify ordinal relationship or a particular physical form and especially one that is allotropic, isomeric, stereoisomeric, or sometimes polymeric (as in β-D-glucose)
2 : second in position in the structure of an organic molecule from a particular group or atom also : occurring at or having a structure characterized by such a position beta substitution
3 : producing a zone of decolorization when grown on blood media used of some hemolytic streptococci or of the hemolysis they cause

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Nglish: Translation of beta for Spanish Speakers

Britannica English: Translation of beta for Arabic Speakers Encyclopedia article about beta

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