Noun | 1. | Mebaral - a long-acting crystalline barbiturate (trade name Mebaral) used as a sedative and as an anticonvulsant in the treatment of epilepsy anticonvulsant, anticonvulsant drug, antiepileptic, antiepileptic drug - a drug used to treat or prevent convulsions (as in epilepsy) barbiturate - organic compound having powerful soporific effect; overdose can be fatal |