store vs pile up

store is a noun but pile up is not a noun.

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

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

Other hyponyms of store include bin, computerise, computerize, victual, accumulate, amass, collect, compile, hoard, roll up, hive.

store (noun)	pile up (noun)
a mercantile establishment for the retail sale of goods or services
a depository for goods
an electronic memory device
a supply of something available for future use

store (verb)	pile up (verb)
keep or lay aside for future use	increase in amount by collecting or gathering
find a place for and put away for storage	arrange into piles or stacks
	get or gather together