repugnant or horrible: gruesomely unpleasant, or creating a sense of horror
[12th century. Ultimately < W Germanic, "terror"]
gris·li·ness noun
Spelling Note
Do not confuse the spelling of grisly and grizzly (a type of bear), which sound similar. Grisly is an adjective meaning "gruesomely unpleasant," as in the grisly remains of the corpse, whereas grizzly is a noun, short for grizzly bear.