- a person or thing that rules or governs
- a thin strip of wood, metal, etc. with a straight edge and markings in whole and fractional units of length, as inches or centimeters, used in drawing straight lines, measuring length, etc.
- a person or device that rules lines on paper, etc.
Jennifer uses a ruler to measure the plant she is growing for an experiment in her science class.
- An example of a ruler is a wooden tool used to measure the length of a piece of paper.
- An example of a ruler is a king.
The definition of a ruler is a strip of wood, plastic or metal used for measuring, or a leader.
- One, such as a monarch or dictator, that rules or governs.
- A straightedged strip, as of wood or metal, for drawing straight lines and measuring lengths. Also called rule .
rule + -er.
- He was the chief ruler of that great city.
- My daughter is the ruler of the immortal world, her father said.
- All that ruler business was just nonsense, but we are friends forever.
- He was a very wise and powerful ruler, and he made his country the greatest of any that was then known.
- She is the Ruler destined to be my successor, for she is a Royal Princess.