the third letter of the Greek alphabet (Γ, γ).
the consonant sound represented by this letter.
the third in a series of items.
Astronomy. Gamma, a star that is usually the third brightest of a constellation.
The third brightest star in the Southern Cross is Gamma Crucis.
a unit of weight equal to one microgram.
Physics. a unit of magnetic field strength, equal to 10− 5 gauss.
Photography. a measure of the degree of development of a negative or print.
Television. an analogous numerical indication of the degree of contrast between light and dark in the reproduction of an image in television.
Chiefly British. a grade showing that an individual student is in the third, or lowest, of three scholastic sections in a class.
the third letter in the Greek alphabet (Γ, γ), a consonant, transliterated as g. When double, it is transcribed and pronounced as ng
the third highest grade or mark, as in an examination
a unit of magnetic field strength equal to 10 –5 oersted. 1 gamma is equivalent to 0.795 775 × 10 –3 ampere per metre
photog television the numerical value of the slope of the characteristic curve of a photographic emulsion or television camera; a measure of the contrast reproduced in a photographic or television image
(modifier)
involving or relating to photons of very high energy
a gamma detector
relating to one of two or more allotropes or crystal structures of a solid
gamma iron
relating to one of two or more isomeric forms of a chemical compound, esp one in which a group is attached to the carbon atom next but one to the atom to which the principal group is attached
From the Greek word gámma
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Eradication was possible through the sterile insect technique, which uses gamma radiation to irradiate screwworm pupae and create sterile male flies.
From Los Angeles Times • Jun. 6, 2026
In 2024, researchers led by Li Shang at Anhui University in Hefei, China, suggested that Fermi's Large Area Telescope may have detected gamma rays from one of these events years after the explosion occurred.
From Science Daily • May 27, 2026
“You have a massive gamma squeeze going on right now in Micron,” said Michael Kramer of Mott Capital Management.
From MarketWatch • May 26, 2026
For every simulation, the researchers calculated both neutrino production and the related gamma ray emission, then compared the results with real observations.
From Science Daily • May 24, 2026
These X rays and gamma rays are like waves of light, but with a much shorter wavelength.
From "A Brief History of Time: And Other Essays" by Stephen Hawking
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
