gamma

1 of 2

noun

gam·​ma ˈga-mə 

plural gammas

1

: the 3rd letter of the Greek alphabet see Alphabet Table

2

: something or someone designated with the name gamma or the Greek letter γ especially denoting the third in position, order, or class

gamma hydroxybutyrate

3

: the degree of contrast of a developed photographic image or of a video image

4

: a unit of magnetic flux density equal to one nanotesla

5

: gamma ray

gamma counter

6

: microgram

gamma

2 of 2

adjective

1

: of, relating to, or being one of three or more closely related chemical substances

2

: third in position in the structure of an organic molecule from a particular group or atom

—symbol γ

Examples of gamma in a Sentence

Recent Examples on the Web

Noun

Other waves are fast and choppy—awake and conscious activity is typically associated with beta (13 to 30 Hz) and gamma waves (roughly 30 to 100 Hz). —Lydia Denworth, Scientific American, 13 June 2023

Seconds after their ventilators were removed, two of the patients’ brains suddenly lit up with a burst of neuronal activity in high-frequency patterns called gamma waves that continued as the heart stopped beating. —Bysara Reardon, science.org, 1 May 2023

Some companies have begun selling devices designed to trigger gamma waves without first proving that the devices are effective. —Ryan Cross, BostonGlobe.com, 22 Mar. 2023

As these rates lag, coronavirus variants that are more transmissible and dangerous than the original strain continue to spread, including the delta variant that’s now dominant in the U.S., the gamma variant in Brazil, and the beta variant in South Africa. —Sarah Jacoby, SELF, 26 Aug. 2021

Delta also lacks the E484K mutation, which has made the gamma variant so worrisome. —Liz Szabo, Quartz, 29 July 2021

So far, experts say, no coronavirus variant among the ones known so far — alpha, beta, delta plus, gamma, lambda and others — rivals delta as a competitor. —San Francisco Chronicle, 21 July 2021

The gamma wave activity of two patients shortly before death is considered the fastest brain activity possible. —Tim Newcomb, Popular Mechanics, 9 May 2023

But the brain activity measurements for two of the patients showed surges in gamma waves after they were taken off life support and experienced cardiac arrest. —Will Sullivan, Smithsonian Magazine, 5 May 2023

Adjective

The company expects these programs to lead to full a gamma version and full production runs by the end of 2024. —IEEE Spectrum, 31 Jan. 2023

And the worldwide shortage of gamma ferric oxide has brought tape production to a crawl. —David Grossman, Popular Mechanics, 11 Oct. 2019

In addition to remaining unperturbed by the outside world, this specific subset of cells tended to spike regularly at gamma-range intervals, like a metronome. —Diana Kwon, Scientific American, 18 July 2019

This revealed phytanic acid (frequently found in the fat and milk of ruminants), azelaic acid (common in wholegrain cereals) and gamma-terpinene (typically found in herbs like coriander). —The Economist, 12 July 2018

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Word History

Etymology

Noun

Middle English, borrowed from Latin, borrowed from Greek gȧmma, borrowed from Phoenician *gaml-, perhaps with the original sense "throwing stick"

Adjective

attributive use of gamma entry 1

First Known Use

Noun

15th century, in the meaning defined at sense 1

Adjective

1834, in the meaning defined at sense 1

Phrases Containing gamma

• gamma camera
• gamma-aminobutyric acid
• gamma globulin
• gamma interferon
• gamma hydroxybutyrate
• interferon gamma
• gamma ray
• gamma ray burst
• gamma radiation

• gamma camera
• gamma-aminobutyric acid
• gamma globulin
• gamma interferon
• gamma hydroxybutyrate
• interferon gamma
• gamma ray
• gamma ray burst
• gamma radiation

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Kids Definition

gamma

noun

gam·​ma

ˈgam-ə

: the third letter of the Greek alphabet

—Γ or γ

Medical Definition

gamma

1 of 2 noun

gam·​ma ˈgam-ə 

1

: the third letter of the Greek alphabet

—symbol Γ or γ

2

: a unit of magnetic flux density equal to one nanotesla

3

: gamma ray

—usually used as the attributive form of gamma ray

gamma counter

4

: microgram sense 1

gamma

2 of 2 adjective

variants or γ-

1

: of or relating to one of three or more closely related chemical substances

the gamma chain of hemoglobin

γ-yohimbine

—used somewhat arbitrarily to specify ordinal relationship or a particular physical form and especially one that is allotropic, isomeric, or stereoisomeric (as in gamma benzene hexachloride)

2

: third 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

γ-hydroxy acids

3

of streptococci : producing no hemolysis on blood agar plates