More gray or gray-streaked, the comparative form of grizzly.
Hair and beards become grizzlier with age: His stubble was grizzlier than I remembered.
The word describes the silvery-gray coloring that comes from aging or weathering, not the bear (though the bear's name comes from the same root—its fur appears frosted with gray).
1. appearance — shaggier, More coarsely overgrown; scruffier (More disheveled in appearance); wilder (To disorient or confuse); rougher (More coarse-textured); coarser · bristlier · hairier · beardier
2. demeanor — grimmer, More severe or bleak; sterner (More demanding, less forgiving); harsher (More severe or unkind); fiercer (More violently intense); tougher · crustier · surlier · gruffer
Opposites
texture/appearancegrizzlier ≠ sleeker More glossy and trim; smoother · silkier · glossier · softer · finer
age/wear appearancegrizzlier ≠ fresher More recently made; newer · dewier
grooming/conditiongrizzlier ≠ neater More orderly; tidier · fresher