tamp down vs tamp

tamp down is not a noun while tamp is a noun.

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

As verbs, tamp down and tamp are synonyms defined as:

Other synonyms of tamp down include pack.

tamp down (noun)	tamp (noun)
	a tool for tamping (e.g., for tamping tobacco into a pipe bowl or a charge into a drill hole etc.)

tamp down (verb)	tamp (verb)
press down tightly	press down tightly