buy in vs understock

buy in and understock both are verbs.

Word	Noun	Adjective	Verb	Adverb
buy in	No	No	Yes	No
understock	No	No	Yes	No

As verbs, understock is a hyponym of buy in; that is, understock is a word with a more specific, narrower meaning than buy in:

buy in: amass so as to keep for future use or sale or for a particular occasion or use
understock: stock with less than the usual or desirable number or quantity

Other hyponyms of buy in include overstock.

buy in (verb)	understock (verb)
amass so as to keep for future use or sale or for a particular occasion or use	stock with less than the usual or desirable number or quantity