c. 1300, from Old French eclipse "eclipse, darkness" (12c.), from Latin eclipsis, from Greek ekleipsis "an eclipse; an abandonment," literally "a failing, forsaking," from ekleipein "to forsake a usual place, fail to appear, be eclipsed," from ek "out" (see ex-) + leipein "to leave" (from PIE root *leikw- "to leave").