WordNet sense 1 (English poet best known for his elegy written in a country churchyard (1716-1771)):

Thomas Gray

WordNet sense 2 (American navigator who twice circumnavigated the globe and who discovered the Columbia River (1755-1806)):

Robert Gray

WordNet sense 3 (United States botanist who specialized in North American flora and who was an early supporter of Darwin's theories of evolution (1810-1888)):

Asa Gray

WordNet sense 4 (any organization or party whose uniforms or badges are grey):

grey

WordNet sense 5 (a neutral achromatic color midway between white and black):

grayness, greyness

WordNet sense 6 (showing characteristics of age, especially having grey or white hair):

grizzly, hoary, gray-haired, gray-headed, grey-haired, grey-headed, hoar, white-haired

WordNet sense 7 ((used especially of persons) having lived for a relatively long time or attained a specific age):

old

WordNet sense 8 (in or characteristic of a region of the United States south of (approximately) the Mason-Dixon line):

southern

WordNet sense 9 (lying between two extremes in time or space or degree):

intermediate, intermediate

WordNet sense 10 (darkened with overcast):

dull, leaden

WordNet sense 11 (full of or covered with clouds):

cloudy

WordNet sense 12 (of an achromatic color of any lightness intermediate between the extremes of white and black):

grayish, greyish

WordNet sense 13 (having no hue):

achromatic