misnomer

A misnomer is a name inappropriately applied to something or someone because it does not fit their nature. To call a bleak swamp Paradise Gardens is to give it a misnomer.  The word came to us from Anglo-Norman, one of the many legal words adopted into English as a result of the Norman Conquest.  The original meaning in law was that a wrong name had been given to someone involved in a court case.  This usage escaped the law courts and generalised to being a name given to someone or something that did not accord with their nature, or that gave a false impression.  The nickname ‘Pixie’ for a robust young woman would be a misnomer.

Of course a humorous word play in which you call someone the opposite of what they are — shorty for a tall person, bluey for a redhead — is not regarded as a misnomer. That is a deliberate joke.

Unfortunately from that generalising process misnomer has drifted to be a synonym for  mistake or misconception or misunderstanding.  It’s a misnomer to think that herbs can cure cancer.  We should make every effort to stamp this out before it becomes the norm. Given the frequency of this usage, especially in American English, it may already be too late.