One that folds or is folded, such as a booklet or pamphlet made of one or more folded sheets of paper.
A flexible cover folded in the center and used as a holder for loose paper: a file folder; a hanging folder.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.