hydantoin vs phenytoin

hydantoin and phenytoin both are nouns.

Word	Noun	Adjective	Verb	Adverb
hydantoin	Yes	No	No	No
phenytoin	Yes	No	No	No

As nouns, phenytoin is a hyponym of hydantoin; that is, phenytoin is a word with a more specific, narrower meaning than hydantoin:

hydantoin: any of a group of anticonvulsant drugs used in treating epilepsy
phenytoin: an anticonvulsant drug (trade name Dilantin) used to treat epilepsy and that is not a sedative

Other hyponyms of hydantoin include Dilantin, diphenylhydantoin.

hydantoin (noun)	phenytoin (noun)
any of a group of anticonvulsant drugs used in treating epilepsy	an anticonvulsant drug (trade name Dilantin) used to treat epilepsy and that is not a sedative