noun Immunology.
- any substance, often a protein, that induces an allergy: common allergens include pollen, grasses, dust, and some medications.
noun
- any substance capable of inducing an allergy
substance causing allergy, 1912, from allergy on model of antigen.
n.
- A substance, such as pollen, that causes an allergy.
- antigen
- A substance, such as pollen, that causes an allergic reaction.