Definition of "beta" []

• The second letter of the Greek alphabet. See Table at 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)
• Physics A beta particle. (noun)
• Physics A beta ray. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

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