noun
: an organ of chemical sense that receives stimuli interpreted as odors from volatile and soluble substances in low dilution, that lies in the walls of the upper part of the nasal cavity, and that forms a mucous membrane continuous with the rest of the lining of the nasal cavity and made up of tall columnar supporting cells containing golden brown pigment interspersed with olfactory cells the outer processes of which project between the supporting cells as small vesicles surmounted by delicate sensory filaments and the inner ends of which are continuous with fibers of the olfactory nerves