Medical Dictionary

H1 antagonist

noun \ˈāch-ˈwən-\

Medical Definition of H1 ANTAGONIST

:  any of numerous drugs (as cetirizine or loratadine) that bind competitively with histamine to H1 receptors on cell membranes and are used variously as sedatives, antiemetics, and anticholinergics—called also H1 receptor antagonist
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears