Meaning of “allergic” - Learner’s Dictionary

allergic

adjective uk us /əˈlɜːdʒɪk/
PERSON [ never before noun ]

having an allergy:

I'm allergic to eggs.
CAUSE [ always before noun ]

caused by an allergy:

an allergic reaction

(Definition of “allergic” from the Cambridge Learner’s Dictionary © Cambridge University Press)