allergy
Medical condition; also used as a suffix in compounds like 花粉アレルギー (pollen allergy).
from German Allergie
I have a cat allergy, so I can't keep a cat.
When pollen allergy season comes, I can't stop sneezing.
aversion; strong dislike
Figurative use; often followed by がある or used as a suffix to express a strong personal distaste for something.
He has an aversion to studying and gets sleepy as soon as he sits at his desk.
I have a strong dislike for getting up early.
I'm allergic to eggs.
I had an allergic reaction after taking this medicine.
I recently developed a pollen allergy.
He feels a strong aversion to authoritarian methods.
allergic reaction
allergen