Crossword Genius

Length of a school ruler (4)

Ross

I believe the answer is:

foot

(Other definitions for foot that I've seen before include "Distance to the end of a limb?" , "Metrical unit; pay (a bill)" , "Base - unit of measurement" , "An imperial length or body part" , "Measure - part of body" .)

I've seen this clue in the USA Today.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.