olfaction

from WordNet (r) 3.0 (2006)

olfaction
    n 1: the faculty that enables us to distinguish scents [syn:
         {smell}, {sense of smell}, {olfaction}, {olfactory
         modality}]

from The Collaborative International Dictionary of English v.0.48

Olfaction \Ol*fac"tion\, n. [See {Olfactory}.] (Physiol.)
   The sense by which the impressions made on the olfactory
   organs by the odorous particles in the atmosphere are
   perceived.
   [1913 Webster]