A surprising bit of etymology — “nice,” it turns out, comes from the Latin “nescius,” meaning “ignorant.” According to the Oxford English Dictionary, “The semantic development of this word from ‘foolish, silly’ to ‘pleasing’ is unparalleled in Latin or in the Romance languages. The precise sense development in English is unclear. N.E.D. (1906) s.v. notes that ‘in many examples from the 16th and 17th cent. it is difficult to say in what particular sense the writer intended it to be taken’.” Go figure.
Oh, and two obsolete definitions (2a and 2b in the OED): “Of conduct, behaviour, etc.: characterized by or encouraging wantonness or lasciviousness” and “Of a person: wanton, dissolute, lascivious” (citing, among other things, “nice wenches” in Shakespeare’s Measure for Measure), not to be confused with 3f, “Respectable, virtuous, decent.” Nice.