plumb line

Meanings

1. 1nouncountable

   A cord with a weight at one end, used to find or check a true vertical line.

   Grammar: Countable: you can say 'a plumb line' or 'two plumb lines'. The weight is often called a plumb bob.

   Patterns

   • use a plumb line
   • hang a plumb line
   • check something with a plumb line

   The builder hung a plumb line from the top of the wall to make sure it was perfectly vertical.

   Before laying the bricks, they used a plumb line to check that the corner was straight.

2. 2nouncountable

   A line that is exactly vertical, as if marked by a plumb line.

   Grammar: Often used figuratively to mean something that is exactly straight up and down.

   Patterns

   • in a plumb line
   • along a plumb line

   The two towers stood in a perfect plumb line with each other.

   The waterfall fell in a straight plumb line into the pool below.

Word forms

Common combinations

hang a plumb line

The surveyor hung a plumb line to establish a vertical reference.

check with a plumb line

Always check the doorframe with a plumb line before installing the door.

plumb line method

The plumb line method is still used in basic carpentry.

drop a plumb line

He dropped a plumb line from the roof to mark the spot on the ground.

Synonyms and how they differ

vertical

A general adjective for anything straight up and down; a plumb line is the physical tool or the exact line it marks.

plumb bob

Refers specifically to the weight at the end of the cord, not the whole line.

Word family

plumb adjective

Exactly vertical, as in 'the wall is plumb'.

plumber noun

A person who installs and repairs water pipes; unrelated in meaning but from the same root (lead).

Commonly confused: plumb line or plum line?

Practice

Make it your own

Write a sentence using “plumb line”, then check it and compare it with the examples above.

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