- (geometry) A line or plane that is perpendicular to another.
- A device such as a plumb line that is used in making or marking a perpendicular line.
New World Encyclopedia writers and editors copied and adjusted this Wiktionary entry in accordance with NWE standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit for this article is due to both New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list acceptable citing formats.The history of earlier contributions at Wiktionary is accessible to researchers here: