1. The absence of the sense of smell or olfactory anesthesia: "The anosmias consist of a lack of sensation of the nerves or fibers located at the top of the nose which normally convert smells into nerve impulses."
2. The complete loss of the sense of smell, usually a result of either a disease of the olfactory mucousa with damage to olfactory end-organs, or to lesions of the olfactory nerve fibers and tracts: "Anosmia may be caused by a head injury with a division of olfactory nerve fibers which are the nerves that carry smell sensations from the nose to the brain."

The loss or absence of the sense of smell or a decreased ability to smell foods: The famous chef was very concerned when he was given a diagnosis of anosmia gustatoria because his profession depended on his ability to smell as well as to taste.