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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.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


the state of being perfectly vertical or plumb
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
In addition to measuring aspects such as floor flatness, levelness and wall plumbness, the new software enables accurate comparisons to the original design files or Building Information Model (BIM) documentation, including as-built positional changes to floors, steel beams, walls, columns, windows and doors.
The process of vibratory pile driving can be concluded that, firstly, the vibratory driving equipment clamps and lifts a pile, after adjusting the plumbness of the pile, and drives it into the soil through the vibration of the vibratory hammer.