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

Another group of oral antihistamines, called H2 antihistamines, block histamine in receptors mostly found in your stomach. —Ruth Jessen Hickman, Health, 12 June 2026

The antihistamine is used in over-the-counter products to treat symptoms such as sneezing, runny nose, watery eyes, hives, skin rash, itching and nausea. —Mary Walrath-Holdridge, USA Today, 12 June 2026

Diphenhydramine is an antihistamine sold under several brand names, including Benadryl, according to MedlinePlus, an online health resource run by the National Library of Medicine. —Byshafiq Najib, ABC News, 10 June 2026

Six years after its emergence, a social media challenge instructing teens to take dangerous levels of Benadryl and other antihistamines is still circulating and Connecticut officials are warning parents after three children in the state have died. —Staff Report, Hartford Courant, 10 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