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 substances in the reports included common household products such as pain relievers, antihistamines, cold medicines and vitamins, the study said. —Madeline Holcombe, CNN Money, 9 Sep. 2025

Take an oral nonprescription antihistamine (Benadryl) or one with loratadine (Alavert, Claritin, others). —Jalen Williams, Freep.com, 29 Aug. 2025

In the bloodstream, the most important of these chemicals is histamine, which is why antihistamines can help in some allergic situations, the researchers explained. —Hannah Millington, MSNBC Newsweek, 28 Aug. 2025

Even if symptoms aren’t life-threatening, if hives are spreading, persisting, or disrupting your ability to function, a dermatologist can provide prescription options that go beyond antihistamines. —Lauryn Higgins, Flow Space, 25 Aug. 2025

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