gamma
1. gam.ma \'gam-*\ n [ME, fr. LL, fr. Gk, of Sem origin; akin to Heb gi-mel gimel] 1: the third letter of the Greek alphabet - symbol G or g 2: the degree of contrast of a developed photographic image or of a televis ion image 3: MICROGRAM 2. gamma or g- aj : third in position in the structure of an organic molecule from a partic ular group or atom