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

This led to severe digestive issues, significant weight loss and extreme food restrictions that required frequent antihistamine use to function. —Tereza Shkurtaj, PEOPLE, 30 May 2026

Night sweats, sleepless nights, brain fog; the search for relief has driven some to get creative in the drugstore aisle, combining daily antihistamines like Allegra or Claritin with antacids like Pepcid AC. —Helen Carefoot, Flow Space, 29 May 2026

There are topical treatments that are antihistamines, mast cell stabilizers or a combination of both. —Neelam Patadia, The Conversation, 27 May 2026

For example, older adults tend to produce less saliva, as well as people with diabetes, Alzheimer’s disease and Sjogren’s syndrome and those taking certain antidepressants, antihistamines and blood pressure drugs. —The New York Times News Service Syndicate, San Diego Union-Tribune, 26 May 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