noun · a physical tool used for marking and measuring right angles

匠人用矩来校准直角。

noun, verb · to engrave or cut into a specific shape

工匠把木料矩成合适的尺寸，准备开始制作桌子。

noun, expression · an established standard, regulation, or pattern of behavior

老师要求我们在课堂上的言行举止要有规有矩。