Real Dictionary

stockpile
countable noun: A stockpile of things is a large quantity of them that have been stored for future use.
verb: If people stockpile things such as food or weapons, they store large quantities of them for future use.

stockpile in American English
a reserve supply of goods, raw material, etc., accumulated esp. in anticipation of future shortage or emergency
to accumulate a stockpile (of)
intransitive verb: to accumulate in a stockpile
noun: a supply of material, as a pile of gravel in road maintenance
transitive verb: to accumulate (material, goods, or the like) for future use; put or store in a stockpile

stockpile in British English
noun: a large store or supply accumulated for future use
verb: to acquire and store a large quantity of (something)

stockpile in Chemical Engineering
noun: A stockpile is a pile of bulk goods.