pull in vs pile up

pull in and pile up both are verbs.

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

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

Other hypernyms of pull in include accumulate, amass, collect, compile, hoard, roll up.

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