The word for today is…
misnomer (noun) – 1. An error in naming a person or place.
2. (a) Application of a wrong name.
(b) A name wrongly or unsuitably applied to a person or object.
Source : The Free Dictionary
Etymology : What’s in a name? Well, in some cases, a name will contain an error, a misunderstanding, or a mislabeling. Historians have long noted that the Holy Roman Empire was neither holy, Roman, nor an empire. The Battle of Bunker Hill was actually fought on Breed’s Hill. And the Pennsylvania Dutch are in fact of German ancestry. For such cases, we have the term misnomer, which comes from the Anglo-French verb mesnomer (“to misname”) and ultimately has its roots in nomen, the Latin word for “name.”