misnomer

The noun is derived from Late Middle English misnoumer (“(law) mistaken identification of a person; plea based on such misidentification”), from Anglo-Norman mesnomer, a noun use of Anglo-Norman mesnomer, mesnommer, and Old French mesnomer, mesnommer (“to name incorrectly”), from mes- (prefix meaning ‘badly, wrongly’) + nomer, nommer (“to name”) (from Latin nōmināre, the present active infinitive of nōminō (“to name”), from nōmen (“name”) (from Proto-Indo-European *h₁nómn̥ (“name”)) + -ō (suffix forming regular first-conjugation verbs)).

The verb is derived from the noun.