Gummed paper, also known as adhesive paper, is a type of paper that has a coating of adhesive on one side. It is commonly used for sealing envelopes, attaching labels, and making crafts. The term 'gummed paper' is derived from the fact that the adhesive was traditionally made from gum arabic. The crossword solution for this term is 'STAMP, ' which refers to the process of applying the adhesive to the paper.