n. 1. The act of moving backward, or of putting or moving anything backward. [ 1913 Webster ]
2. That which is behind, and forms the back of, anything, usually giving strength or stability. [ 1913 Webster ]
3. Support or aid given to a person or cause. [ 1913 Webster ]
4. (Bookbinding) The preparation of the back of a book with glue, etc., before putting on the cover. [ 1913 Webster ]