I. ˌGeneral ˈMotors BrE AmE trademark abbreviation , GM
one of the world's largest car companies, which is based in the US and has factories in many countries. Its ↑ make s (=types) of cars and trucks include Chevrolet, Cadillac, Oldsmobile, Pontiac, and Buick, and in Europe, Opel and Vauxhall.
II. GM /ˌdʒiː ˈem/ BrE AmE adjective British English
(genetically modified) GM foods or plants have had their ↑ genetic structure changed so that they are not affected by particular diseases or harmful insects