grit
noun
°Collection of hard small materials, such as dirt, ground stone, debris from sandblasting or other such grinding, swarf from metalworking.
"The flower beds were white with grit from sand blasting the flagstone walkways."
°Inedible particles in food.
"Tastes like grit from nut shells in these cookies."
verb
°To clench, particularly in reaction to pain or anger; apparently only appears in gritting one's teeth.
"We had no choice but to grit our teeth and get on with it."
°To cover with grit.