Real Dictionary

near-death experience
countable noun: A near-death experience is a strange experience that some people who have nearly died say they had when they were unconscious.

near-death experience in American English
an experience, usually deeply felt and transformative, of a person near death; often, specif., one which the person later reports had been the occasion of, variously, a feeling of out-of-body awareness, a blissful vision of an afterlife, etc.
noun: any experience involving a vision, as of the afterlife, reported by a resuscitated person

near-death experience in British English
noun: an experience, instances of which have been widely reported, in which a person near death is apparently outside his or her body and aware of it and the attendant circumstances as separate from him