Answer:

grit

Answer	Crossword Clue
GRIT	Backbone
GRIT	Sandpaper feature
GRIT	Stick-to-itiveness

GRIT	Can't eat just one
GRIT	Indomitable spirit
GRIT	The Duke's "True .."
GRIT	True determination
GRIT	Pluck
GRIT	Sandpaper coating
GRIT	Tough personal fiber
GRIT	Determination

GRIT	John Wayne's "True .."
GRIT	Fortitude
GRIT	"True ...:" Wayne film
GRIT	Gumption
GRIT	True courage
GRIT	"True ..": John Wayne film
GRIT	Moxie
GRIT	Abrasive bits

GRIT	Mettle
GRIT	Sandpaper coarseness measure
GRIT	Sandstorm residue
GRIT	Spunk
GRIT	"True ..": Wayne film
GRIT	Courage
GRIT	"True ..." (Wayne film)
GRIT	Sandy stuff

GRIT	Guts
GRIT	"True ..."
GRIT	Stick-to-it-iveness
GRIT	Pluckiness
GRIT	Clamp together, as teeth
GRIT	Firmness of character
GRIT	Indomitable fortitude
GRIT	"True ..." (John Wayne movie)

GRIT	Abrasive material
GRIT	Boldness
GRIT	Sandpaper spec
GRIT	Courage; spunk
GRIT	"True ...": Wayne film