gamma Look up gamma at Dictionary.com
third letter of the Greek alphabet, c.1400, from Greek gamma, from Phoenician gimel, said to mean literally "camel" (see camel) and to be so called for a fancied resemblance of its shape to some part of a camel. Gamma rays (1903) originally were thought to be a third type of radiation, but later were found to be very short X-rays.