Overweening means showing far too high an opinion of yourself. Overweening ambition, overweening pride, overweening confidence.
It nearly always goes with pride, ambition or confidence, and it is a heavy criticism. The ween in it is an old verb meaning to think or expect, so overweening is thinking too much of yourself.
1adjectiveoverweeningShowing far too high an opinion of yourself.
“His overweening ambition eventually cost him all his friends.”
overweening is a quality.
From overween, to think too highly of oneself, from the old verb ween, to think.
Middle English
overweninge
English, today
overweening
From Middle English overweninge, equivalent to overween + ing. Cognate with obsolete Dutch overwanig, overwaand (“presumptuous; cocky; conceited”).
Etymology from Wiktionary, CC BY-SA