1. (

• gray ,
• Gy

) 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 ;

1. (

• G.I. ,
• GI

) clean in preparation for inspection; "the soldiers GIed the barracks" ;

1. (

• gastrointestinal ,
• GI

) of or relating to the stomach and intestines; "a gastrointestinal disorder" ;