grav·el 
(grăvəl)
(grăvəl)n.
1. An unconsolidated mixture of rock fragments or pebbles.
2. Medicine The sandlike granular material of urinary calculi.
tr.v. grav·eled, grav·el·ing, grav·els or grav·elled or grav·el·ling
1. To apply a surface of rock fragments or pebbles to.
2. To confuse; perplex.
3. Informal To irritate.
[Middle English, from Old French gravele, diminutive of grave, pebbly shore, of Celtic origin.]