ruler
sovereign / monarch
[C/U] Both
pl: rulers
The word carries a sharp duality between physical precision and political power. When referring to a tool, it evokes a sense of rigidity, standardization, and exactness, often associated with schooling or technical drafting.
Countable when referring to a specific leader or a physical measuring tool. Uncountable when used in the archaic sense of the act of ruling.
Meanings
Nounsovereign
A person who exercises government or sovereignty over a territory.
"The benevolent ruler brought peace to the land."
Nounmonarch
A straight strip of wood, plastic, or metal used for measuring length or drawing straight lines.
"She used a ruler to draw the margin on her paper."