histamine

noun

his·​ta·​mine ˈhi-stə-ˌmēn  -mən 

: a compound C₅H₉N₃ especially of mammalian tissues that causes dilation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion, that is released during allergic reactions, and that is formed by decarboxylation of histidine

Examples of histamine in a Sentence

Recent Examples on the Web

Two other conditions that have gained attention online, mast cell activation syndrome (MCAS) and histamine intolerance, involve different processes and can cause symptoms that overlap with those of allergies. — Lauren Finney Harden, AJC.com, 20 Oct. 2026

Colds and allergies have similar symptoms like sneezing, runny noses and watery eyes, which is why they can both be treated by a histamine-blocking medication that can help dry up your sinuses. — Andee Tagle, NPR, 15 Oct. 2026

Clozapine also has complex interactions with other neurotransmitter pathways, including those involving acetylcholine, histamine, and norepinephrine, which contribute to its pharmacological and toxicity profile. — Encyclopedia Britannica, 7 Oct. 2026

Some scientists speculate that acetaldehyde might trigger a release of the immune-signalling chemical histamine, leading to alcohol-intolerance symptoms. — Shayla Love, New Yorker, 26 Aug. 2026

Word History

Etymology

International Scientific Vocabulary hist- + amine

First Known Use

circa 1913, in the meaning defined above

Rhymes for histamine

• acridine
• acrolein
• adenine
• alkylene
• aniline
• anthracene
• aquiline
• asphaltene
• atlantean
• atrazine
• butadiene
• butylene

Kids Definition

histamine

noun

his·​ta·​mine ˈhis-tə-ˌmēn 

-mən

: a compound that occurs in many animal tissues and plays an important part in allergic reactions (as in hives, asthma, and hay fever)

Medical Definition

histamine

noun

his·​ta·​mine ˈhis-tə-ˌmēn  -mən 

: a compound C₅H₉N₃ especially of mammalian tissues that causes dilatation of capillaries, contraction of smooth muscle, and stimulation of gastric acid secretion, that is released during allergic reactions, and that is formed by decarboxylation of histidine

histaminic

ˌhis-tə-ˈmin-ik 

adjective