gamma

[ gam-uh ]

noun

1. the third letter of the Greek alphabet (Γ, γ).
2. the consonant sound represented by this letter.
3. the third in a series of items.
4. Gamma, Astronomy. a star that is usually the third brightest of a constellation:

   The third brightest star in the Southern Cross is Gamma Crucis.

5. a unit of weight equal to one microgram.
6. Physics. a unit of magnetic field strength, equal to 10− 5 gauss.
7. Photography. a measure of the degree of development of a negative or print.
8. Television. an analogous numerical indication of the degree of contrast between light and dark in the reproduction of an image in television.
9. Chiefly British. a grade showing that an individual student is in the third, or lowest, of three scholastic sections in a class. Compare alpha ( def 8 ), beta ( def 9 ).

Gamma

¹

/ ˈɡæmə /

noun

1. foll by the genitive case of a specified constellation the third brightest star in a constellation

   Gamma Leonis

gamma

²

/ ˈɡæmə /

noun

1. the third letter in the Greek alphabet (Γ, γ), a consonant, transliterated as g. When double, it is transcribed and pronounced as ng
2. the third highest grade or mark, as in an examination
3. a unit of magnetic field strength equal to 10 ^–5oersted. 1 gamma is equivalent to 0.795 775 × 10 ^–3ampere per metre
4. 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
5. modifier
   1. involving or relating to photons of very high energy

      a gamma detector

   2. relating to one of two or more allotropes or crystal structures of a solid

      gamma iron

   3. 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

Word History and Origins

Origin of gamma¹

From the Greek word gámma

Word History and Origins

Origin of gamma¹

C14: from Greek; related to Hebrew gīmel third letter of the Hebrew alphabet (probably: camel)

Example Sentences

We were herded into hastily set-up clinics to get shots of gamma globulin, which was thought to boost our immune systems.

From Salon

Light that reaches our telescopes ranges in wavelength from long radio waves to energetic gamma rays.

From Salon

The research team were simultaneously monitoring a source of gamma rays and seeking a fast radio burst when they spotted the object slowly flashing in the data.

From Science Daily

The water board demanded the cities to submit plans by April to scan these areas for cancer-causing gamma radiation and sample for banned pesticides, including DDT.

From Los Angeles Times

At specific frequencies of light and sound, the flicker treatment can induce gamma oscillations in mice.

From Science Daily