noun ダウンロード 🔗共有 仙骨 A large triangular bone at the base of the spine, located between the two ilia (wings of the pelvis) and formed from vertebrae that fuse in adulthood. Examples : "The doctor examined the patient's lower back, focusing on the sacrum where it connected to the pelvis. " 医者は患者の腰部を診察し、骨盤と接続する仙骨に焦点を当てた。 anatomy body medicine physiology part structure human organ AIとチャット語彙ゲーム読解練習