overweening means unduly confident; (sometimes also) arrogant. Lexicurio rates it Rare gem — a strength score of 72 out of 100.
overweening is pronounced /əʊvəˈwiːnɪŋ/.
Why “overweening” is a great word
OVERWEENING — [Adjective] Showing excessive confidence or arrogance; exaggerated or presumptuous. From Middle English overweninge, from overween (to be arrogant or presumptuous, from over- + ween "to think, suppose") + the suffix -ing. Unlike "confident," which implies justified self-assurance, or "presumptuous," which denotes taking unwarranted liberties, overweening describes a vast, atmospheric inflation of the self. It is the strut of a minor official in an empty hall, the serene smile of the dilettante dismissing a master's work, and the grandiose plan built on a single grain of sand—a pride so vast it finally imprisons the mind within its own fragile architecture.
Etymology
From Middle English overweninge, equivalent to overween + -ing. Cognate with obsolete Dutch overwanig, overwaand (“presumptuous; cocky; conceited”).
adj
- Unduly confident; (sometimes also) arrogant.“She wins one modeling contest in Montana and suddenly she’s overweening.”
- Exaggerated, excessive.“The idea that an overweening federal government is a threat to both freedom and equality (not to mention prosperity) goes back to Jefferson, James Madison, Patrick Henry and some other fairly respectable personages.”
noun
- An excessively high opinion of oneself or one’s abilities; presumption, arrogance.“Let us suppresse this over-weening [translating cuider], the first foundation of the tyrannie of the wicked spirit[…].”