a wrong or inappropriate name
misnomer - misnaming
A ‘misnomer’ is a name that does not suit what it refers to. It typically implies something contradictory or paradoxical that creates the unsuitability. This word is most commonly seen in written English, particularly in print media, and is almost always preceded by the determiner 'a'.
It’s a total misnomer to refer to our technology as ‘cutting edge’ because most of it is at least ten years old by now.
The fact that the country is called ‘Greenland’ is a misnomer because it is mostly covered in snow and ice.
Even though David is technically a diplomat, the job title is something of a misnomer because he is generally outspoken and tactless.