墨すみ縄なわ

noun

inked marking string; snap line

A carpenter's tool: a string coated with ink, pulled taut and snapped to leave a straight line on wood or other materials. Also used figuratively for a guideline or standard.

• 大だい工くは墨すみ縄なわを使つかって木もく材ざいに直ちょく線せんを引ひいた。

  The carpenter used an inked marking string to draw a straight line on the lumber.

• このプロジェクトでは、安あん全ぜん基き準じゅんを墨すみ縄なわとして守まもらなければならない。

  In this project, we must follow the safety standards as our guideline.