beta

1 of 2

noun

be·​ta ˈbā-tə 

chiefly British

ˈbē- 

plural betas

1

: the 2nd letter of the Greek alphabet see Alphabet Table

2

: something or someone designated with the name beta or the Greek letter β especially denoting the second in position, order, or class

3

: 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

The app is still in beta.

4

: beta particle

beta emissions

5

: 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

Beta measures a stock's price volatility—or risk—compared with the market in general …

—Marlys J. Harris

6

: beta wave

The findings could also help scientists better understand other beta-associated disorders, such as Parkinson's disease or obsessive compulsive disorder …

—Brown University News Release (Providence, Rhode Island)

beta

2 of 2

adjective

: 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

Code hidden within the latest beta version of the Google app for Android reveals that preparation is underway for the Galaxy S25 Edge to receive a promotional Google Gemini Advanced plan at launch, currently valued at $19.99 per month. —Paul Monckton, Forbes, 20 Mar. 2025

Though each Mickey is Mickey, the dynamic that emerges between Mickey 17 and his double, Mickey 18, is that of beta and alpha. —Fran Hoepfner, Vulture, 13 Mar. 2025

Adjective

Importantly, this update is being released for beta users—those are people who signed up to get the latest features first. —Ryan Whitwam, Ars Technica, 6 Mar. 2025

Most importantly, test your idea with beta clients before making big investments as this helps validate demand and refine your offer without financial risk. —Melissa Houston, Forbes, 1 Mar. 2025

Word History

Etymology

Noun

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

First Known Use

Noun

14th century, in the meaning defined at sense 1

Adjective

1862, in the meaning defined above

Phrases Containing beta

• A-beta
• amyloid beta
• amyloid beta peptide
• amyloid beta protein
• beta-adrenergic
• beta-amyloid
• beta-amyloid peptide
• beta-amyloid protein
• beta-blocker
• beta-carotene
• beta cell
• beta decay
• beta-endorphin
• beta globulin
• beta-glucan
• beta hydroxy acid
• beta interferon
• beta-lactamase
• beta-oxidation
• beta particle
• beta ray
• beta-receptor
• beta test
• beta-thalassemia
• beta wave
• interferon beta

Rhymes for beta

• data
• theta
• zeta
• oligochaeta
• peseta
• punctata
• polychaeta

Kids Definition

beta

noun

be·​ta

ˈbāt-ə

: the 2nd letter of the Greek alphabet

—Β or β

Medical Definition

beta

1 of 2 noun

be·​ta

ˈbāt-ə, chiefly British ˈbē-tə

1

: the second letter of the Greek alphabet

—symbol Β or β

2

: beta particle

3

: beta wave

beta

2 of 2 adjective

variants or β-

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