Webster's Revised Unabridged Dictionary · 1913

Odorant

Odorant , adjective

[Latin odorans, -antis, p. pr.]

Yielding odors; fragrant. — Holland

odorant , noun

An odorous substance;
a substance with a strong odor added to a dangerous substance, such as natural gas, to provide an easy detection method and a warning; as, ethyl mercaptan is used as an odorant in natural gas and propane to facilitate detection of leaks.