1. a substance that causes an allergic reaction in a person or animal
Usage: commonly used in medical and scientific contexts

Examples

• Pollen is a common allergen that affects many people in spring.
• The food label clearly lists all potential allergens like peanuts and shellfish.
• Dust mites are a major household allergen for people with asthma.
• Her doctor identified pet dander as the primary allergen triggering her symptoms.
• The restaurant staff was trained to handle customers with severe allergen sensitivities.
• Latex gloves can be an allergen for some healthcare workers.
• Air filters help reduce allergens in the home.