Definition

1. Noun:
   • A weight attached to a line for determining verticality: A "plumb bob" is a heavy, symmetrical metal weight, typically pointed at the bottom, that is suspended from a string or line (a plumb line). It uses gravity to establish a true vertical reference line or to check if a surface is perfectly vertical.

Examples of Usage

• Noun:
  • The carpenter used a plumb bob to ensure the wall was straight.
  • Before hanging the door, check its alignment with a plumb bob.

Advanced Usage

• "To drop a plumb bob": To use a plumb bob to measure or establish a vertical line.
  • The surveyor dropped a plumb bob from the marked point on the bridge.

Variants and Related Words

• Plumb line (n): The complete tool consisting of the line and the attached plumb bob.
• Plumb (v): To test or measure the vertical alignment of something using a plumb bob or plumb line.
  • He plumbed the corner of the new construction.

Synonyms

• Plummet: Often used interchangeably with "plumb bob," though "plummet" can also refer more generally to any heavy weight on a line.
• Bob: A shorter, informal term for the weighted part itself.

Related Phrases

• "Out of plumb": Not vertical; not aligned correctly with a true vertical line as determined by a plumb bob.
  • The old fence post was several inches out of plumb.

Noun

1. the metal bob of a plumb line