Standard Lemma guide

mephenytoin

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • General-American: /məˈfɛn.ɪˌtoʊ.ɪn/

1

noun

Meaning 1

An anticonvulsant drug C12H14N2O2.

Definition source: English Wiktionary via Wiktextract

Usage: uncountable

Topics: medicine, pharmacology, sciences

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a toxic anticonvulsant drug (trade name Mesantoin) used in the treatment of epilepsy when less toxic anticonvulsants have been ineffective

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: Mesantoin

Antonyms: none provided

Broader terms: anticonvulsant, anticonvulsant drug, antiepileptic, antiepileptic drug

History

Etymology

From me(thyl) + pheny(l) + -toin (“hydantoin derivative”).