store vs amass

store is a noun but amass is not a noun.

Word	Noun	Adjective	Verb	Adverb
store	Yes	No	Yes	No
amass	No	No	Yes	No

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

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

store (noun)	amass (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)	amass (verb)
keep or lay aside for future use	increase in amount by collecting or gathering
find a place for and put away for storage	get or gather together