Definitions:

1. A criterion or standard against which something is evaluated or judged, generally used in making decisions. NOUN
   • Customer satisfaction is the yardstick by which we measure our company's success.
2. A measuring tool that is exactly one yard long, typically made of wood, metal, or plastic. NOUN
   • The carpenter grabed the yardstick to check the length of the wooden board.
3. A physical tool for measuring length, equal to three feet. NOUN
   • Using a yardstick, she marked exactly where to cut along the edge.

Synonyms:

• guideline
• measure
• measuring stick
• ruler
• standard
• yard measure