dump vs knock down

dump is a noun but knock down is not a noun.

Word	Noun	Adjective	Verb	Adverb
dump	Yes	No	Yes	No
knock down	No	No	Yes	No

As verbs, dump and knock down are synonyms defined as:

Other synonyms of dump include coldcock, deck, floor.

dump (noun)	knock down (noun)
a place where supplies can be stored
(computer science) a copy of the contents of a computer storage device; sometimes used in debugging programs
a piece of land where waste materials are dumped
a coarse term for defecation

dump (verb)	knock down (verb)
knock down with force	shatter as if by explosion
drop (stuff) in a heap or mass	knock down with force
fall abruptly	cause to come or go down
throw away as refuse
sell at artificially low prices
sever all ties with, usually unceremoniously or irresponsibly