rul·er 
/ˈru:lɚ/ noun
plural rul·ers /ˈru:lɚ/ noun [count] 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. — see picture at carpentry
▪ a summit attended by a number of rulers from around the world
▪ This ruler shows inches and centimeters. — see picture at carpentry
