ruler ruler /ˈruːlɝ/

noun

1. () A person who rules or commands  ( swayer , ruler )
   a person who rules or commands
    Swayer of the universe
   swayer of the universe
   
2. () Measuring stick consisting of a strip of wood, metal or plastic with a straight edge that is used for drawing straight lines and measuring lengths  ( rule , ruler )
   measuring stick consisting of a strip of wood, metal or plastic with a straight edge that is used for drawing straight lines and measuring lengths
    I use a ruler to draw straight lines in my notebooks
   I use a ruler to draw straight lines in my notebooks