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

The doctor prescribed 5 milligrams of the anxiety medication buspirone twice daily, as well as 25 milligrams of hydroxyzine – an antihistamine that would have similar effects to Benadryl – daily. — Melina Khan, USA Today, 11 Aug. 2026

She was given a course of antibiotics and antihistamines, and told to wait three days for the swelling to go down before getting the false lashes removed. — Kelly McGreal, FOXNews.com, 9 Aug. 2026

Acute reactions are managed according to their severity, with antihistamines used for mild symptoms and intramuscular epinephrine administered for anaphylaxis. — Encyclopedia Britannica, 5 Aug. 2026

Because itching is often triggered by histamine (a chemical in the body associated with immune responses), dermatologists had reason to think that antihistamines could effectively subdue the itching caused by eczema. — Rob Williams, EverydayHealth.com, 30 July 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