noun
inked marking string; standard
Refers to a carpenter's inked string used for marking straight lines, and by extension a standard or rule. The 'standard' sense is a figurative extension of the tool.
大工は縄墨を使って木材に直線を引いた。
The carpenter used an inked marking string to draw a straight line on the lumber.
彼の行動は社会の縄墨から外れている。
His behavior deviates from the standards of society.