What is the X in X-mas?
early 13c., "fragrant substance," from Latin aroma "sweet odor," from Greek aroma "seasoning, any spice or sweet herb," of unknown origin. Meaning "fragrance" is from 1814. A hypercorrect plural is aromata.
the property of certain substances, in very small concentrations, to stimulate chemical sense receptors that sample the air or water surrounding an animal. In insects and other invertebrates and in aquatic animals, the perception of small chemical concentrations often merges with perception via contact of heavy concentrations (taste), and with other chemoreceptive specializations. See also smell.