Epilepsy, ep-1-lep'sy, a disease of the brain. It is characterized by a loss of consciousness and muscular spasms. The ancients called it the "sacred disease," fancying that one in an epileptic fit was taken possession of by a familiar spirit. In case of an attack there is little to be done, save to loosen the patient's clothing and see that he comes to no harm from falling. One subject to epilepsy is likely to suffer a loss of memory and to become despondent.