a. [ Superl. of Over. ] Uppermost; outermost. [ 1913 Webster ]
Full threadbare was his overeste courtepy. Chaucer. [ 1913 Webster ]
v. t. 1. To estimate too highly. [ 1913 Webster ]
2. Hence: To overvalue. [ PJC ]
n. An estimate that is too high; as, an overestimate of the vote. [ 1913 Webster ]