mow vs cut down

mow is a noun but cut down is not a noun.

Word	Noun	Adjective	Verb	Adverb
mow	Yes	No	Yes	No
cut down	No	No	Yes	No

As verbs, mow and cut down are synonyms defined as:

mow (noun)	cut down (noun)
a loft in a barn where hay is stored

mow (verb)	cut down (verb)
make a sad face and thrust out one's lower lip	cut down on; make a reduction in
cut with a blade or mower	intercept (a player)
	cause to come or go down
	cut with a blade or mower
	cause to fall by or as if by delivering a blow
	cut with sweeping strokes; as with an ax or machete