overweening (adj.)

mid-15c. (mid-14c. as overweenende, with the earlier ending), present-participle adjective from verb overwenen "be conceited or arrogant, think too highly or confidently (especially of oneself); be presumptuous, be over-confident" (mid-14c.), from over- + ween or else from Old English oferwenian "to be proud, become insolent or presumptuous." Middle English also had overwēne (n.) "presumption, arrogance" (mid-13c.); overwēnere "one who is presumptuous or arrogant."