ruler UK /ˈɹuːlə/US /ˈɹulɚ/noun 2verb 1forms 3 noun2 •A person who rules or governs; someone or something that exercises dominion or controlling power over others.The carcharhinids are unquestionably the rulers of the seas, because of their abundance, their strength and speed, and their unchallenged position as the number one predators in the marine ecosystem. — 1983 •A (usually rigid), flat, rectangular measuring or drawing device with graduations in units of measurement; a straightedge with markings.Take this ruler. […] I want you to measure the glass of the lamp. — 1914 verb1 •To beat with a ruler (as a traditional school punishment). formsrulered · rulering · rulers
