PRESUMP'TUOUS, adjective 1. Bold and confident to excess; adventuring without reasonable ground of success; hazarding safety on too slight grounds; rash; applied to persons; as a presumptuous commander. There is a class of presumptuous men whom age has not made cautious, nor adversity wise. 2. Founded on presumption; proceeding from excess of confidence; applied to things; as presumptuous hope. 3. Arrogant; insolent; as a presumptuous priest. Presumptuous pride. 4. Unduly confident; irreverent with respect to sacred things. 5. Willful; done with bold design, rash confidence or in violation of known duty; as a presumptuous sin.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI