Is Straightedge One Word or Two?

a bar or strip of wood, plastic, or metal having at least one long edge of sufficiently reliable straightness for use in drawing or testing straight lines, plane surfaces, etc.

What is the definition of straightedge?

: a bar or piece of material (as of wood, metal, or plastic) with a straight edge for testing straight lines and surfaces or for cutting along or drawing straight lines.

How is a ruler different from straightedge?

A ruler has a proper width between two clearly defined parallel lines. It can be rectangular or triangular. A straightedge is simply a narrow stick-like instrument that does not have a specified width based on parallel lines. Rulers can be of different lengths, as longer rulers are used to measure longer lengths.