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Glite Dictionary
plumb rule

plumb rule

7.9
A straight narrow board with a hanging weight used to check if a wall is perfectly vertical
  • noun
  • /plʌm ruːl/
  • Specialized
translation icon : regla de plomada
  • The carpenter used a plumb rule to ensure the wall was perfectly upright.

Examples

  • Before spirit levels were common, builders relied on the trusty plumb rule for vertical alignment.

  • Can you hand me the plumb rule from the toolbox?

  • Even in modern construction, a plumb rule can be useful for checking accuracy.

  • The carpenter used a plumb rule to ensure the wall was straight.

  • The carpenter used a plumb rule to check if the door frame was perfectly vertical.

  • In old buildings, workers often depend on a plumb rule to ensure walls are straight.

  • Before installing shelves, he measured with a plumb rule to confirm they would be level.

Synonyms

plumb line
vsplumb rule
  • Specialized
1 5.3

A string with a metal weight that shows a straight up-and-down line

attaches the cord to a straight board to check if surfaces are perfectly vertical
plumb level
vsplumb rule
  • Specialized
7.2

A tool with a hanging string and a bubble level to check vertical or horizontal lines

focuses solely on vertical alignment rather than checking horizontal alignment

How Accurate

plumb line
  • Specialized
1 5.3
plumb rule
  • Specialized
7.9
level
  • Specialized
145 3.2

Surface Forms

plumb rule singular
plumb rules plural

Morphology

plumb + rule

The meaning is directly compositional: a 'rule' (straight-edged measuring tool) that includes a 'plumb' (a weighted bob for vertical alignment). This noun–noun combination follows a transparent instrument-with-component pattern, so a B1 learner who knows both constituent meanings can infer the MWE's sense.

Etymology

Plumb rule comes from an old building tool: a straight narrow board with a hanging plumb line (a weight on a string) used as a rule to check if a surface was perfectly 'vertical'. Builders held the plumb rule against a wall and watched the hanging line to see if the wall was truly upright, so the name means a device for checking 'vertical' alignment.