store vs ROM

store and ROM both are nouns.

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

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

store: an electronic memory device
ROM: (computer science) memory whose contents can be accessed and read but cannot be changed

store (noun)	ROM (noun)
a mercantile establishment for the retail sale of goods or services	(computer science) memory whose contents can be accessed and read but cannot be changed
a depository for goods
an electronic memory device
a supply of something available for future use

store (verb)	ROM (verb)
keep or lay aside for future use
find a place for and put away for storage