MIS- n.
erbially in the sense of amiss, wrong, ill, wrongly, unsuitably; as, misdeed, mislead, mischief, miscreant.
MISTRESS n.
A woman having power, authority, or ownership; a woman who exercises authority, is chief, etc.; the female head of a family, a school, etc. The late queen's gentlewoman! a knight's daughter! To be her mistress' mistress! Shak.