c. 1600, from French épileptique, from Late Latin epilepticus, from Greek epileptikos, from stem of epilambanein "to seize" (see epilepsy). Earlier adjective was epilentic (late 14c.), from a Greek variant. As a noun from 1650s.
epileptic seizure
epigone
epigram
epigrammatic
epigraph
epilepsy
epileptic
epilogue
epinephrine
epiphany
epiphenomenon
epiphyte