a device that shreds documents (usually in order to prevent the wrong people from reading them)
shredder详细解释
shred.der
n.(名词) One that shreds. 切碎机,粉碎机 A device used for shredding documents, often as a security measure to prevent unapproved persons from reading them. 碎纸机:用以切碎文件的机器,常用作避免未经授权的人得以阅读该文件的安全措施