(ˈ)mis|dēm, -i|stēm verb
Etymology: Middle English misdemen, from mis- (I) + demen to deem — more at deem
transitive verb
1. archaic : to judge unfavorably : think badly of
made him to misdeem my loyalty — Edmund Spenser
2.
a. : to have a mistaken opinion of : misjudge
misdeemed the power of the opposition
a gruffness that led us to misdeem their true intentions
b. : to think or suppose wrongly
but he misdeems that he is wise — P.B.Shelley
3. : to mistake for something or someone else
misdeem fantasy for reality
intransitive verb
: to be mistaken : hold a wrong opinion
farther on, if I misdeem not — H.F.Cary