The petrous bone is located in the inner ear and it is one of the hardest and densest bones in the human body. This bone is also known as the petrous portion of the temporal bone. Some synonyms for petrous bone are petrosal bone, petrous pyramid, and petrobasilar bone. The word petrosal refers to the density and hardness of the bone, while the term pyramid denotes its shape. The petrous bone is an important structure as it houses many delicate structures such as hearing and balance organs. Understanding the synonyms of the petrous bone will help in better communication between physicians and medical professionals.