Definition
An insidious disease is any disease that comes on slowly and does not have obvious symptoms at first. The person is not aware of its development.
References
Taber's Cyclopedic Medical Dictionary. 24th ed. Insidious. Philadelphia, PA: F.A. Davis Company; 2021. www.tabers.com/tabersonline/view/Tabers-Dictionary/770775/all/insidious. Accessed June 13, 2023.