Definition of "straightedge" []

• A rigid flat rectangular bar, as of wood or metal, with a straight edge for testing or drawing straight lines. (noun)

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.

• "The lines will not be perfectly straight, even if drawn with a "straightedge.""
• "Professionals use a long straightedge to detect them."
• "They would be impressed if you could trisect an angle using only a compass and straightedge."