overween
/ˌəʊvəˈwiːn/verb
1 [no object] To have excessively or unreasonably high expectations; to be conceited, arrogant, or presumptuous; to be too self-confident.
2 [with object] To overrate or think too highly of. Also refl.: to have too high an opinion of oneself. Now rare.
Origin
Middle English; earliest use found in Ayenbite of Inwyt. From over- + ween.