Is it ensure, insure, or assure?
c.1600, from French épileptique, from Late Latin epilepticus, from Greek epileptikos, from epilambanein (see epilepsy). Earlier adjective was epilentic (late 14c.), from a Greek variant. As a noun from 1650s.
epileptic ep·i·lep·tic (ěp'ə-lěp'tĭk)
One who has epilepsy. adj.
Affected with epilepsy.
Of, relating to, or associated with epilepsy.