antihistamine

noun

an·​ti·​his·​ta·​mine ˌan-tē-ˈhi-stə-ˌmēn 

-mən, 

ˌan-tī-

: any of various compounds that counteract histamine in the body and that are used for treating allergic reactions (such as hay fever) and cold symptoms

antihistamine adjective

antihistaminic

ˌan-tē-ˌhi-stə-ˈmi-nik 

ˌan-tī-

adjective or noun

Examples of antihistamine in a Sentence

Recent Examples on the Web

For now, antihistamines and certain other drugs for hives can tamp down some itchiness triggered by mast cells. — ABC News, 27 June 2026

Reishi is not a same-day fix the way a pharmacy antihistamine can be, and its benefits build gradually as the compounds work on the immune system over time. — Samantha Agate, Kansas City Star, 26 June 2026

Unlike conventional antihistamines, which block histamine after it has been released, reishi may help regulate the allergic response at multiple points in the immune system. — Samantha Agate, Miami Herald, 26 June 2026

Apply a cold compress, and consider taking an antihistamine to help with itching. — Arricca Elin Sansone, Southern Living, 22 June 2026

Word History

First Known Use

1946, in the meaning defined above

Kids Definition

antihistamine

noun

an·​ti·​his·​ta·​mine ˌant-i-ˈhis-tə-ˌmēn 

-mən, 

ˌan-ˌtī-

: any of various drugs used for treating allergic reactions and cold symptoms

Medical Definition

antihistamine

1 of 2 adjective

an·​ti·​his·​ta·​mine ˌant-i-ˈhis-tə-ˌmēn, ˌan-ˌtī-, -mən 

: tending to block or counteract the physiological action of histamine

human blood lacks antihistamine activity

antihistamine

2 of 2 noun

: any of various compounds that oppose the actions of histamine and are used especially for treating allergic reactions (as hay fever), cold symptoms, and motion sickness