- The definition of a T square is a t-shaped ruler with a thick piece at one end that can slide on an edge used for making straight, parallel lines.
An example of a T square is what an architect would use on their draft table when making straight lines in a building design.
T square definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a -shaped ruler with a short, thick crosspiece that fits over the edge of a drawing board, used in drawing parallel lines
T square definition by American Heritage Dictionary
A rule having a short, sometimes sliding, perpendicular crosspiece at one end, used by drafters for establishing and drawing parallel lines.