toss away vs dump

toss away is not a noun while dump is a noun.

Word	Noun	Adjective	Verb	Adverb
toss away	No	No	Yes	No
dump	Yes	No	Yes	No

As verbs, dump is a hyponym of toss away; that is, dump is a word with a more specific, narrower meaning than toss away:

toss away (noun)	dump (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

toss away (verb)	dump (verb)
throw or cast away	knock down with force
	drop (stuff) in a heap or mass
	fall abruptly
	throw away as refuse
	sell at artificially low prices
	sever all ties with, usually unceremoniously or irresponsibly