grit

grit 1

•  noun [U]
• 

1    very small pieces of stone or sand
2    informal determination and courage
gritty adjective

 grit 2

• verb [T] -tted, -tting

1    grit your teeth to use all your determination to keep going in a difficult or painful situation
2    to put grit on a frozen road to make it less SLIPPERY