Entry 2 senses Webster, 1913 allergic · IPA /əˈlɝ.d͡ʒɪk/ 01 adj. of or pertaining to allergy. 1. of or pertaining to allergy. 2. having an allergy or peculiar or excessive susceptibilty especially to a specific factor Syn. hypersensitive, hypersensitized, sensitized, supersensitive, supersensitized