adj. | 1. relating to or involving the belief that something is being seen, heard, or otherwise sensed when it is not present or actually occurring at the time 2. causing somebody to believe that he or she is seeing, hearing, or otherwise sensing things that are not present or actually occurring at the time 4. similar to a hallucination 1. relating to or involving the belief that something is being seen, heard, or otherwise sensed when it is not present or actually occurring at the time 2. causing somebody to believe that he or she is seeing, hearing, or otherwise sensing things that are not present or actually occurring at the time 4. similar to a hallucination |