IDDM uncommon noun 1. severe diabetes mellitus with an early onset; characterized by polyuria and excessive thirst and increased appetite and weight loss and episodic ketoacidosis; diet and insulin injections are required to control the disease Synonymstype I diabetesinsulin-dependent diabetes mellitusjuvenile-onset diabetesjuvenile diabetesgrowth-onset diabetesketosis-prone diabetesketoacidosis-prone diabetesautoimmune diabetes Related words Broader terms diabetes mellitusautoimmune disease Part of ketoacidosis WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.