Grisly means ghastly or gruesome.
- The prosecutor painted a grisly picture of the event.
Gristly means composed of or containing gristle.
- The children gave the dog the gristly end to chew.
Grizzled means partly gray or streaked with gray.
- Our leader today is a grizzled veteran of many mountain climbs.
Grizzly is a bear.
- The grizzly bear is the greatest symbol of the wilderness.