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

Then there’s the pharmacy’s worth of other sleep aids travelers sometimes turn to: prescription pills like Ambien or Ativan, antihistamines like Benadryl, or even CBD. —Bailey Berg, AFAR Media, 23 May 2025

And so can one specific antihistamine, hydroxyzine. —Bruce Y. Lee, Forbes.com, 15 May 2025

Medications to treat allergic angioedema, like antihistamines, are unlikely to work on HAE symptoms.3 Does hereditary angioedema get worse with age? —Sarah Hudgens, Health, 22 Apr. 2025

Anyone who’s ever waged war with the pollen count knows that the best over-the-counter (OTC) allergy treatment is a good old-fashioned antihistamine. —Sara Coughlin, SELF, 15 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