spine

词汇归类：ky toefl

单词定义：n. a small sharp-pointed tip resembling a spike on a stem or leaf n. the part of a book's cover that encloses the inner side of the book's pages and that faces outward when the book is shelved n. a sharp rigid animal process or appendage; as a porcupine quill or a ridge on a bone or a ray of a fish fin