noun (n)

• the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form(noun.cognition)

  Synonym:
  odor, olfactory perception, olfactory sensation, smell
  

  source: wordnet30
• any property detected by the olfactory system(noun.attribute)

  Synonym:
  aroma, odor, olfactory property, scent, smell
  

  source: wordnet30