pile up vs pull in

pile up and pull in both are verbs.

Word	Noun	Adjective	Verb	Adverb
pile up	No	No	Yes	No
pull in	No	No	Yes	No

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

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

pile up (verb)	pull in (verb)
increase in amount by collecting or gathering	direct toward itself or oneself by means of some psychological power or physical attributes
arrange into piles or stacks	get or bring together
get or gather together	of trains; move into (a station)
	earn on some commercial or business transaction; earn as salary or wages