What is the definition or description of: deja vu?

"Already Seen": Déjà vu is a feeling that a current event or experience has been experienced previously. It is thought to be an aberration of memory in which the "time stamp" of an event becomes mis-assigned to make it seem as if the event occurred previously. Almost everyone has experienced rare déjà vu events. When frequent it is rarely associated with temporal lobe epilepsy.