plumb line

noun

1. a cord with a lead bob attached to one end, used to determine perpendicularity, the depth of water, etc. Compare plumb ( def 1 ).
2. plumb rule.

plumb line

noun

1. a string with a metal weight at one end that, when suspended, points directly towards the earth's centre of gravity and so is used to determine verticality, the depth of water, etc
2. another name for plumb rule

plumb line

/ plŭm /

1. A line regarded as directed exactly toward the Earth's center of gravity.

Word History and Origins

Origin of plumb line¹

First recorded in 1530–40

Example Sentences

They worked with simple plumb lines and slates for recording depths and satchels full of explosives for destroying obstacles.

From Popular-Science

When I took down the remaining wallpaper in preparation for new wallpaper, I came across all her notes, measurements and marks for plumb lines.

From Washington Post

On either side of this isolated bar of sandstone a plumb-line might have been dropped straight to the level of the river.

From Project Gutenberg

Supports of dressed stone truly fixed with the plumb line are perfectly stable of themselves.

From Project Gutenberg

Dæd´alus is also mentioned as the inventor of the axe, plumb-line and augur.

From Project Gutenberg

Titiens then in a formal manner laid the first brick, using the plumb-line to ascertain that the work had been properly done.

From Project Gutenberg

He found a magnetic ridge line running approximately parallel to the line of no deflection of the plumb line.

From Project Gutenberg