noun 下载 🔗分享 骶骨 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. " 医生检查了病人的下背部,重点检查了骶骨与骨盆连接的部位。 anatomy body medicine physiology part structure human organ 与AI对话词汇游戏阅读练习