buy at vs frequent

buy at is not an adjective while frequent is an adjective.

Word	Noun	Adjective	Verb	Adverb
buy at	No	No	Yes	No
frequent	No	Yes	Yes	No

As verbs, buy at and frequent are synonyms defined as:

buy at and frequent: do one's shopping at; do business with; be a customer or client of

Other synonyms of buy at include patronise, patronize, shop, shop at, sponsor.

buy at (adjective)	frequent (adjective)
	coming at short intervals or habitually
	frequently encountered

buy at (verb)	frequent (verb)
do one's shopping at; do business with; be a customer or client of	be a regular or frequent visitor to a certain place
	do one's shopping at; do business with; be a customer or client of