hydantoin vs antiepileptic drug

hydantoin and antiepileptic drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydantoin	Yes	No	No	No
antiepileptic drug	Yes	No	No	No

As nouns, antiepileptic drug is a hypernym of hydantoin; that is, antiepileptic drug is a word with a broader meaning than hydantoin:

hydantoin: any of a group of anticonvulsant drugs used in treating epilepsy
antiepileptic drug: a drug used to treat or prevent convulsions (as in epilepsy)

Other hypernyms of hydantoin include anticonvulsant, anticonvulsant drug, antiepileptic.

hydantoin (noun)	antiepileptic drug (noun)
any of a group of anticonvulsant drugs used in treating epilepsy	a drug used to treat or prevent convulsions (as in epilepsy)