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

Which Meds Aren’t Safe To Use Daily? Generally, antihistamines, as well as antihistamines combined with decongestants, aren’t recommended for long-term use. —Jillian Kubala, Health, 28 Apr. 2025

Of course, there are the usual treatments—antihistamines, nasal sprays, decongestants, etc.—but what about a shot to relieve your symptoms? —Thomas G. Moukawsher, MSNBC Newsweek, 24 Apr. 2025

The treatment has demonstrated significantly better outcomes than antihistamines in small randomized trials, requiring only one dose two weeks before pollen and grass season. —Dylan Scott, Vox, 15 Apr. 2025

Just keep in mind, too, that all antihistamines have some potential side effects, Dr. Bielory notes, like dry mouth, dry eyes, and constipation. —Erica Sloan, SELF, 2 Apr. 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