gamma

IPA/ˈɡæmə/
KK[ɡˈæmə]IPA/ˈɡæmə/

gamma — noun

  • gammasingular
  • gammasplural

1. the name and written symbol (Γ, γ) of the third character in the Greek writing s

1.nounB1
Definition

the name and written symbol (Γ, γ) of the third character in the Greek writing system, used widely in mathematics and science to represent angles, constants, and other values

Example

In her Greek language class, Mei learned that the letter gamma comes third, right after alpha and beta.

third letter in Greek alphabet sequence

During the physics exam, Priya used a small gamma to label the second angle.

Common collocations
  • uppercase gamma
  • lowercase gamma
  • the letter gamma
  • gamma symbol

Grammar Patterns

the letter gamma

gamma as a symbol

2. a powerful form of energy that travels through space as invisible waves, given o

2.nounB2
Definition

a powerful form of energy that travels through space as invisible waves, given off by radioactive materials, nuclear reactions, and certain events in space; used in medicine to treat cancer and in factories to kill harmful germs

Example

The hospital uses gamma rays to shrink tumours without cutting open the body.

gamma rays in medical treatment

Thick lead walls are needed to block gamma radiation from escaping the lab.

gamma radiation requires lead shielding

Common collocations
  • gamma ray burst
  • gamma radiation
  • gamma knife
  • emit gamma rays
  • detect gamma radiation
  • gamma irradiation
Synonyms
  • gamma ray

    the countable, photon-focused form of the same concept — 'gamma rays' are individual rays, while 'gamma radiation' is the overall emission

  • gamma radiation

    the uncountable form emphasising the continuous emission rather than individual photons

Grammar Patterns

gamma rays

gamma radiation

Usage Note

The countable form 'gamma ray' refers to individual photons of this radiation; the uncountable 'gamma radiation' describes the emission as a whole. Distinguished from sense 1 by scientific context — this sense never refers to the letter symbol itself.

Common Mistakes

The doctor used gamma to treat the patient.
The doctor used gamma rays to treat the patient.
'gamma' alone does not mean radiation; you need 'gamma ray' or 'gamma radiation' in a scientific context.
Gamma is a type of radioactive wave.
Gamma radiation is a type of electromagnetic wave produced by radioactive materials.
gamma rays are electromagnetic, not 'radioactive waves.'

gamma — adjective

Synonym discussion

Sense: noun/1

Alpha, beta, gamma, and delta are the first four letters of the Greek alphabet and are widely used as a naming system in science. Alpha (α) marks the first item in a sequence, such as the alpha particle or the alpha carbon in a molecule. Beta (β) follows as the second — beta decay and beta blockers are common examples. Gamma (γ) occupies the third position: gamma rays are the third type of radiation discovered, and the gamma carbon is three bonds from the reference group. Delta (δ) indicates the fourth position, seen in terms like delta ray or the delta variant of a virus. In practice, if you see 'alpha' in a term, the 'beta' and 'gamma' versions usually exist too — for instance, alpha, beta, and gamma globulins in blood plasma. The sequence helps scientists quickly communicate order without naming each variant individually.

alpha ↗beta ↗delta ↗

Common collocations

Nouns

Phrases

  • alpha, beta, and gamma
  • gamma ray burst
  • gamma knife surgery
  • gamma correction

Prepositions

Etymology

PhoenicianGreekLatinEnglish

The word 'gamma' comes from the Greek letter name γάμμα (gámma), which was adapted from the Phoenician letter gīml, meaning 'camel' — the original letter shape was thought to resemble a camel's neck. The Phoenician gīml was borrowed into early Greek around the 8th century BCE, where it became the third letter of the alphabet with the sound /g/. Through Latin and later scientific Latin, the term entered English as the name of the letter itself. Its use as a prefix for the third in a series (gamma rays, gamma globulin) follows the scientific convention of using Greek letters as labels, a practice that became common in the 19th and early 20th centuries.