pile up vs collect

pile up is not a noun while collect is a noun.

Word	Noun	Adjective	Verb	Adverb
pile up	No	No	Yes	No
collect	Yes	Yes	Yes	Yes

As verbs, collect is a hypernym of pile up; that is, collect is a word with a broader meaning than pile up:

Other hypernyms of pile up include garner, gather, pull together.

As verbs, pile up and collect are synonyms defined as:

Other synonyms of pile up include accumulate, amass, compile, hoard, roll up.

As verbs, collect is a hyponym of pile up; that is, collect is a word with a more specific, narrower meaning than pile up:

Other hyponyms of pile up include run up, corral, pull in, come up, scrape, scrape up, scratch, chunk, lump, bale, catch, fund, fund.

pile up (noun)	collect (noun)
	a short prayer generally preceding the lesson in the Church of Rome or the Church of England

pile up (adjective)	collect (adjective)
	payable by the recipient on delivery

pile up (verb)	collect (verb)
increase in amount by collecting or gathering	assemble or get together
arrange into piles or stacks	get or bring together
get or gather together	get or gather together
	call for and obtain payment of
	gather or collect

pile up (adverb)	collect (adverb)
	make a telephone call or mail a package so that the recipient pays