WordNet (r) 3.0 (2006):

GD
    n 1: a nerve agent easily absorbed into the body; a lethal
         cholinesterase inhibitor that is highly toxic when inhaled
         [syn: soman, GD]
    2: a ductile silvery-white ductile ferromagnetic trivalent
       metallic element of the rare earth group [syn: gadolinium,
       Gd, atomic number 64]

The Free On-line Dictionary of Computing (30 December 2018):

gd

    The country code for Grenada.

   (1999-01-27)