odour vs olfactory sensation

odour and olfactory sensation both are nouns.

Word	Noun	Adjective	Verb	Adverb
odour	Yes	No	No	No
olfactory sensation	Yes	No	No	No

As nouns, odour and olfactory sensation are synonyms defined as:

odour and olfactory sensation: the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form

Other synonyms of odour include odor, olfactory perception, smell.

odour (noun)	olfactory sensation (noun)
any property detected by the olfactory system	the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form
the sensation that results when olfactory receptors in the nose are stimulated by particular chemicals in gaseous form