Anosmia

n. loss of the sense of smell

Anosmia is the lack of olfaction, or a loss of the ability to smell. It can be either temporary or permanent. A related term, hyposmia, refers to a decrease in the ability to smell, while hyperosmia refers to an increased ability to smell. Some people may be anosmic for one particular odor. This is called "specific anosmia" and may be genetically based.
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The term anosmia means lack of the sense of smell. It may also refer to a decreased sense of smell. [more]Anosmia - Community and Resources

Noun
1. absence of the sense of smell (as by damage to olfactory nasal tissue or the olfactory nerve or by obstruction of the nasal passages)
(hypernym) dysomia

n. anosmia, loss of the sense of smell