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

Foods rich in vitamin C, such as guava, bell peppers, and strawberries, may help with allergy relief by naturally acting as antihistamines and decreasing inflammation. —Kelly Burch Published, Verywell Health, 23 July 2025

About 50% of people with CSU don’t respond to antihistamine treatments and need something else, especially because CSU manifests as an autoimmune condition. —Megan Pregmon, Flow Space, 23 July 2025

Patients now have a clearer hierarchy of options beyond antihistamines, allowing for personalized treatment. —New Atlas, 17 July 2025

Newer antihistamines, like Claritin and Zyrtec, are safer and cause less drowsiness, the paper says. —Cathy Nelson, Health, 16 July 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