: a lead weight attached to a line and used to indicate a vertical direction
1
: straight down or up : vertically
2
chiefly dialectal
: to a complete degree : absolutely
'you're plumb crazy', she remarked, with easy candor—
Harper's Weekly
Harper's Weekly3
: in a direct manner : exactly
also
: without interval of time : immediately
plumbed; plumbing; plumbs
1
: to weight with lead
2
a
: to measure the depth of with a plumb
b
: to examine minutely and critically
plumbing the book's complexities
3
: to adjust or test by a plumb line
4
: to seal with lead
5
[back-formation from plumber]
: to supply with or install as plumbing
: to work as a plumber
Examples of plumb in a Sentence
Adverb
He set the board plumb.
I plumb forgot about the party.
Verb
The book plumbs the complexities of human relationships.
a scientist who spent her life plumbing the minds of criminals
The play plumbs the depths of human nature.
The plumber is almost finished plumbing the apartment.
The new house has been wired and plumbed.
All the bathroom fixtures have been plumbed.
Adjective
The carpenter made sure that the wall was plumb.
a horror movie that's plumb trash and further evidence of the deterioration of popular culture
Recent Examples on the Web
Eric Lach, The New Yorker, 3 Feb. 2025
There’s a wealth of themes to plumb, from familial trauma to addiction to sexism to the tyranny of genius, but its core exploration of the sacrifice required to be an artist is exhilarating, brutal, and intoxicating.
—Ew Staff, EW.com, 11 Dec. 2024
Laura Collins-Hughes, New York Times, 21 Apr. 2025
The German composer, whose work often plumbed the ancient past, came across them in 1934.
—Tim Greiving, Los Angeles Times, 12 Mar. 2025
Jonathon Keats, Forbes.com, 29 Apr. 2025
Mars will appear plumb against its sparkling stars tonight — though the couple of nights either side will also give a great binocular view.
—Jamie Carter, Forbes, 6 Mar. 2025
See All Example Sentences for plumb
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Noun
In 1990, when the angle passed five degrees, and the top of the tower was fifteen feet out of plumb, the structure was said to be finally in danger of collapsing.
—Eric Lach, The New Yorker, 3 Feb. 2025
There’s a wealth of themes to plumb, from familial trauma to addiction to sexism to the tyranny of genius, but its core exploration of the sacrifice required to be an artist is exhilarating, brutal, and intoxicating.
—Ew Staff, EW.com, 11 Dec. 2024
Verb
And the authors, who were in their late 20s and early 30s when the show was new, seem to have been skittish about plumbing their caver’s scarier emotions.
—Laura Collins-Hughes, New York Times, 21 Apr. 2025
The German composer, whose work often plumbed the ancient past, came across them in 1934.
—Tim Greiving, Los Angeles Times, 12 Mar. 2025
Adjective
Artists were enlisted to plumb surreality and to popularize it.
—Jonathon Keats, Forbes.com, 29 Apr. 2025
Mars will appear plumb against its sparkling stars tonight — though the couple of nights either side will also give a great binocular view.
—Jamie Carter, Forbes, 6 Mar. 2025
See All Example Sentences for plumb
Cite this Entry
“Plumb.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/plumb. Accessed 28 May. 2025.
Copy CitationKids Definition
plumb
1 of 4 noun
: a weight attached to a line especially to show a vertical direction or distance
plumb
2 of 4 adverb1
: straight down or up : vertically
2
chiefly dialect
: to a complete degree : absolutely
3
: in a direct manner : exactly
plumb
3 of 4 verb1
: to measure, adjust, or test with a plumb
plumb a wall
plumb the depth of the well
2
: to see into and come to understand
plumbed their motives
plumb
4 of 4 adjective
: exactly vertical or true
the wall is plumb
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