1. Odor hallucinations that include smelling things that do not come from any real physical stimulus: "A person may experience phantosmias which range from rotting flesh to freshly-mowed grass, although most examples of these conditions report unpleasant aromas; so, phantosmia specializes in presenting the disagreeable."

"In some experiences, phantosmia has even given the impression to the afflicted individual that both the odor and source actually exist which is a condition known as pseudosmias or olfactory delusions."

"Both the upper nasal passages and the brain play a part in phantosmia; especially, the brain which generates the smell perception and phantosmia is connected to certain psychiatric disorders, including, schizophrenia, Alzheimer's, and depression."

2. Etymology: phanto, ""; osmia from Greek osme, "smell".