indent - 1. To set (the first line of a paragraph, for example) in from the margin. 2a. To cut or tear (a document with two or more copies) along an irregular line so that the parts can later be matched for establishing authenticity. b. To draw up (a document) in duplicate or triplicate. 3a. To notch or serrate the edge of; make jagged. b. To make notches, grooves, or holes in (wood, for example) for the purpose of mortising. c. To fit or join together by or as if by mortising. 4. Chiefly British To order (goods) by purchase order or official requisition.