periodontal disease pe·rio·don·taldisease uncommon noun 1. a disease that attacks the gum and bone and around the teeth Synonymsperiodontal diseaseperiodontitis Related words Broader terms disease Narrower terms pyorrheaalveolar resorptiongingivitisulatrophia WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.