allergy

/ˈæl.əɹ.d͡ʒi/

Proposed by a contributor, not yet supported by evidence.

Also seen as: allergies

Sense 1

Meaning · English

A disorder of the immune system causing adverse reactions to substances (allergens) not harmful to most and marked by the body's production of histamines and associated with atopy, anaphylaxis, and asthma; any condition of hypersensitivity to a substance.

Noun

Examples

My dad can't live with pets because of an allergy.

Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Sense 2

Meaning · English

A disorder of the immune system causing adverse reactions to substances (allergens) not harmful to most and marked by the body's production of histamines and associated with atopy, anaphylaxis, and asthma; any condition of hypersensitivity to a substance. — Specifically, hypersensitivity of class I in the modern classification thereof: the immunoglobulin E–mediated type.

Noun

Sources & notes

Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).

Common questions

What does “allergy” mean?

A disorder of the immune system causing adverse reactions to substances (allergens) not harmful to most and marked by the body's production of histamines and associated with atopy, anaphylaxis, and asthma; any condition of hypersensitivity to a substance.

Is “allergy” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.