— gnashingly , adv.
/nash/ , v.t.
1. to grind or strike (the teeth) together, esp. in rage or pain.
2. to bite with grinding teeth.
v.i.
3. to gnash the teeth.
n.
4. an act of gnashing.
[ 1490-1500; var. of obs. gnast, ME gnasten; cf. ON gnastan gnashing of teeth ]