Definition, Meaning & Synonyms

allergic reaction

noun
/əˈlɜːrdʒɪk riˈækʃən/
Definition
An allergic reaction is a response by the immune system to a substance that is usually harmless to most people.
Examples
  • After eating peanuts, she experienced a severe allergic reaction.
  • His allergic reaction to the pollen made it hard for him to breathe.
  • Common signs of an allergic reaction include hives, swelling, and difficulty breathing.
Meaning
When the body’s immune system reacts to a foreign substance (allergen) as if it were a threat, leading to various symptoms.
Synonyms
  • Hypersensitivity
  • Allergy response
  • Immune response