noun. an anti-convulsant drug: the prototype of the hydantoins. Phenytoin is recommended primarily for the controlling of tonic-colonic and partial seizures but is also utilized in the remediation of some instances of neuralgia and migraine. It is sometimes utilized to control behavioral disruptions in kids. American brand name: Dilantin.
PHENYTOIN: "Beth's seizures are almost non-existent now that she has been taking the Phenytoin."