refill vs merchandise

refill and merchandise both are nouns.

Word	Noun	Adjective	Verb	Adverb
refill	Yes	No	Yes	No
merchandise	Yes	No	Yes	No

As nouns, merchandise is a hypernym of refill; that is, merchandise is a word with a broader meaning than refill:

refill: a commercial product that refills a container with its appropriate contents
merchandise: items for sale to the individual consumer

Other hypernyms of refill include product, ware.

refill (noun)	merchandise (noun)
a commercial product that refills a container with its appropriate contents	items for sale to the individual consumer
a prescription drug that is provided again	branded products meant to promote another product, especially films and pop groups

refill (verb)	merchandise (verb)
fill something that had previously been emptied	engage in the trade of