plural rulers
1
: a person (such as a king or queen) who rules a country, area, group, etc.
a summit attended by a number of rulers from around the world
2
: a straight piece of plastic, wood, or metal that has marks on it to show units of length and that is used to measure things
This ruler shows inches and centimeters.
Cite this Entry
“Ruler.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/ruler. Accessed 19 Jun. 2026.
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