What is the scientific term for "عجب الذنب" in English, and where is it located in the human body?

"A-jbu Adh-dhanab" (the coccyx) is the small, mighty bone at the base of the spine, at the end of the vertebrae, between the buttocks. It is to humans what the tail is to animals. It is also called "A-jbu Adh-dhanab," "A-jmu Adh-dhanab," and "Al-Us'us." From it, creation will be reassembled on the Day of Resurrection.