Wordnet 3.0
NOUN (1)
1. 
 the SI unit of energy absorbed from ionizing radiation; 
 equal to the absorption of one joule of radiation energy by one kilogram of matter; 
 one gray equals 100 rad; 
[syn: gray, Gy]
WordNet (r) 3.0 (2006):
Gy
    n 1: the SI unit of energy absorbed from ionizing radiation;
         equal to the absorption of one joule of radiation energy by
         one kilogram of matter; one gray equals 100 rad [syn:
         gray, Gy]
The Free On-line Dictionary of Computing (30 December 2018):
gy
    The country code for Guyana.
   (1999-01-27)