Definitions:

1. characterized by or caused by allergy adjective
   • an allergic reaction
2. having an allergy or peculiar or excessive susceptibility, especially to a specific factor adjective
   • It is not uncommon to be allergic to certain pets.

Synonyms:

• hypersensitised
• hypersensitive
• hypersensitized
• sensitised
• sensitized
• supersensitised
• supersensitive
• supersensitized