a book prepared for use in schools or colleges; "his economics textbook is in its tenth edition"; "the professor wrote the text that he assigned students to buy"
deeply affected or marked by mental or physical pain or injury; "Could her scarred mind ever be free of fear?"; "a face scarred by anxiety"; "the fire left her arm badly scarred"
a statistical relation between two or more variables such that systematic changes in the value of one variable are accompanied by systematic changes in the other