diphenhydramine

[ dahy-fen-hahy-druh-meen ]
/ ˌdaɪ fɛnˈhaɪ drəˌmin /

noun Pharmacology.

a white, crystalline, antihistaminic compound, C17H21NO, used orally, topically, and parenterally, especially for allergies.

Origin of diphenhydramine

First recorded in 1945–50; diphen(yl) + hydr-2 + amine