Dr.Dre. Picture: AP

Rapper Dr. Dre has lost his longstanding legal battle with a gynaecologist of the same name.

Dr. Drai, a Pennsylvania-based gynaecologist in 2015 filed to trademark his name and "Doctor Drai OBGYN and Media Personality" and won the right to keep using his trademark name, reports TMZ. 

Although Dr Drai's talents lie in the anatomy of the human body, the rapper had tried to pump the brakes on that application, claiming it would cause confusion in the marketplace since their names sound alike.

But according to the gynaecologist's application, he has been going by the name Dr. Drai for years. He has authored books and has even made public appearances using it. 

The trademark office agreed with the medical doctor, saying although the rapper was well known there was not enough evidence people would be confused.