1848, originally of substances to quell the odor of manure, formed in English as if from de- + Latin odorem "smell" (see odor (n.)). In reference to a substance to be used on the human body, from 1860. An earlier version, a perfumed powder, was called empasm (1650s), from Greek *empasma "to sprinkle on."
1. I use unperfumed roll-on deodorant.
2. She applies deodorant to her armpits after she showers.
3. He rubbed some deodorant under his armpits before dressing.