beta

(bāt′ə; chiefly Brit bēt′ə)

noun

the second letter of the Greek alphabet (Β, β)
the second of a group or series
Astron. the name assigned to the second brightest star in each constellation: followed by the constellation's name in the genitive case, as Beta Geminorum
Comput. a version of software distributed to selected users for testing before sale
Finance a measure of the impact of a change in the stock market on the probable price change of a stock or stocks

Origin: L < Gr bēta < Heb bet, lit., house; prob. of Phoen orig.

adjective

Chem. designating an organic structural position

In full Betamax

See beta in American Heritage Dictionary 4

noun

The second letter of the Greek alphabet. See Table at alphabet.
The second item in a series or system of classification.
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.
Physics
a. A beta particle.
b. A beta ray.
Chemistry
a. The second position from a designated carbon atom in an organic molecule at which an atom or a radical may be substituted.
b. An isomeric variation of a chemical compound. Used in combination: beta-estradiol.
Computer Science A beta version.