trimethadione

noun
tri·​metha·​di·​one | \ ˌtrī-ˌmeth-ə-ˈdī-ˌōn How to pronounce trimethadione (audio) \

Medical Definition of trimethadione

: a crystalline anticonvulsant C6H9NO3 used chiefly in the treatment of absence seizures — see tridione