Small, loose particles of stone or sand. The wind blew grit into their eyes as they walked along the beach.
Courage and resolve; strength of character. It takes a lot of grit to start a new business in a competitive market.
Coarsely ground hulled corn boiled as a porridge; a dish made from this, chiefly in the southern United States (usually in plural as "grits"). They served cheese grits with breakfast.