grind down vs grind

grind down is not a noun while grind is a noun.

Word	Noun	Adjective	Verb	Adverb
grind down	No	No	Yes	No
grind	Yes	No	Yes	No

grind down (noun)	grind (noun)
	the act of grinding to a powder or dust
	hard monotonous routine work
	the grade of particle fineness to which a substance is ground
	an insignificant student who is ridiculed as being affected or boringly studious

grind down (verb)	grind (verb)
rule a country as a tyrant	reduce to small pieces or particles by pounding or abrading
	make a grating or grinding sound by rubbing together
	press or grind with a crushing noise
	shape or form by grinding
	created by grinding
	dance by rotating the pelvis in an erotically suggestive way, often while in contact with one's partner such that the dancers' legs are interlaced
	work hard