Relating to the resin extracted from the stem of the herb Dorema ammoniacum: Ammoniac is quite strong-smelling and was formally used as a stimulant, as a perfume, or even used in cement for porcelain.

Pertaining to ammonia, a gaseous compound consisting of nitrogen and hydrogen: When Jane opened the jar, she couldn't breathe in because of the ammoniac smell that escaped from the inside.