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1. A weight on the end of a line, used to determine water depth.
2. A weight on the end of a line, used especially by masons and carpenters to establish a true vertical.
1. In a vertical or perpendicular line.
2. Informal Directly; squarely: fell plumb in the middle of the puddle.
3. also plum Informal Utterly; completely: plumb worn out. right
1. Exactly vertical. See Synonyms at vertical.
2. also plum Informal Utter; absolute; sheer: a plumb fool.
v. plumbed, plumb·ing, plumbs
1. To determine the depth of with a plumb; sound.
2. To test the verticality or alignment of with a plumb.
3. To straighten or make perpendicular: plumb up the wall.
4. To examine closely or deeply; probe: "Shallow ideas are plumbed and discarded" (Gilbert Highet).
5. To seal with lead.
6. To outfit with or connect to a plumbing system: plumbed the utility closet so a washing machine could be installed.
To work as a plumber.
off/out of plumb
Not vertical.

[Middle English, lead, a plumb, from Old French plomb, from Latin plumbum, lead.]

plumb′a·ble adj.
plumb′ness n.


the state of being perfectly vertical or plumb
References in periodicals archive ?
This means we must work within extraordinarily tight tolerances that take into account movement and shifting of formwork, shrinkage, creeping, and deflection of the concrete, and we must constantly monitor for true and plumbness of the columns and slab edge.
For example, the uncertainties of the fitted coefficients of the cylinder centerline are needed to check, with a given confidence, if two pipes are parallel or to check the plumbness of a cylinder column.
Moving shoring between bridges is an acceptable construction practice, but only when bridges are identical (which was not the case with the MD Route 198 bridges) and the shoring is thoroughly inspected for structural damage and plumbness when relocated, the board said.