Grind, as molars (5)
I believe the answer is:
gnash
(Other definitions for gnash that I've seen before include "Grind away" , "Grind (teeth) together" , "Grind one's teeth" , "champ" , "Strike one's teeth together in rage" .)
I believe the answer is:
gnash
(Other definitions for gnash that I've seen before include "Grind away" , "Grind (teeth) together" , "Grind one's teeth" , "champ" , "Strike one's teeth together in rage" .)