grit in WordNet English dictionary

1. fortitude and determination
   "he didn't have the guts to try it"
   backbone  grit  guts  moxie  sand  gumption 
   
2. a hard coarse-grained siliceous sandstone
   grit  gritrock  gritstone 
   

1. clench together
   "grit one's teeth"
   grit 
   
2. cover with a grit
   "grit roads"
   grit