/spaɪn/
noun
The series of bones situated at the back from the head to the pelvis of a person, or from the head to the tail of an animal; backbone, vertebral column.Something resembling a backbone, such as a ridge, or a long, central structure from which other structures radiate.A pointed, fairly rigid protuberance or needle-like structure on an animal, shell, or plant.The heartwood of trees.Courage or assertiveness.The stiffness of an arrow.