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• plumb
  plumb

  noun

  a small mass of lead or other heavy material, as that suspended by a line and used to measure the depth of water or to ascertain a vertical line.
• Plumb
  Plumb

  noun

  J(ohn) H(arold), 1911–2001, British historian.

plumb

¹ American  

[pluhm] / plʌm /

noun

• plumbs
  plural

1. a small mass of lead or other heavy material, as that suspended by a line and used to measure the depth of water or to ascertain a vertical line.

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adjective

1. true according to a plumb line perpendicular.

   Synonyms:

   square, straight, vertical

2. Informal. downright or absolute.

adverb

1. in a perpendicular or vertical direction.

2. exactly, precisely, or directly.

3. Informal. completely or absolutely.

   She was plumb mad. You're plumb right.

verb (used with object)

• plumbs,
  present (3rd person singular)
• plumbed,
  past participle,  past
• plumbing
  present participle

1. to test or adjust by a plumb line.

2. to make vertical.

3. Shipbuilding. horn.

4. to sound with or as with a plumb line.

5. to measure (depth) by sounding.

6. to examine closely in order to discover or understand.

   to plumb someone's thoughts.

7. to seal with lead.

8. to weight with lead.

9. to provide (a house, building, apartment, etc.) with plumbing.

verb (used without object)

• plumbs,
  present (3rd person singular)
• plumbed,
  past participle,  past
• plumbing
  present participle

1. to work as a plumber.

idioms

1. out of / off plumb, not corresponding to the perpendicular; out of true.

Plumb ² American  

[pluhm] / plʌm /

noun

1. J(ohn) H(arold), 1911–2001, British historian.

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plumb British  

/ plʌm /

noun

1. a weight, usually of lead, suspended at the end of a line and used to determine water depth or verticality

2. the perpendicular position of a freely suspended plumb line (esp in the phrases out of plumb, off plumb )

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adjective

1. informal (prenominal) (intensifier)

   a plumb nuisance

adverb

1. in a vertical or perpendicular line

2. informal (intensifier)

   plumb stupid

3. informal exactly; precisely (also in the phrase plumb on )

verb

1. to test the alignment of or adjust to the vertical with a plumb line

2. (tr) to undergo or experience (the worst extremes of misery, sadness, etc)

   to plumb the depths of despair

3. (tr) to understand or master (something obscure)

   to plumb a mystery

4. to connect or join (a device such as a tap) to a water pipe or drainage system

Other Word Forms

Derived Forms

• plumbness
  noun
• replumb
  verb (used with object)
• plumbable
  adjective
• plumbless
  adjective
• unplumb
  adjective

Inflected Forms

Nouns

• plumbs
  plural

Participles

• plumbing
  present
• plumbed
  past

Conjugated Forms

Present

• plumb
  simple
• plumbs
  simple
• have plumbed
  perfect
• has plumbed
  perfect
• am plumbing
  progressive
• are plumbing
  progressive
• is plumbing
  progressive
• have been plumbing
  perfect progressive
• has been plumbing
  perfect progressive

Past

• plumbed
  simple
• had plumbed
  perfect
• was plumbing
  progressive
• were plumbing
  progressive
• had been plumbing
  perfect progressive

Future

• will plumb
  simple
• will have plumbed
  perfect
• will be plumbing
  progressive
• will have been plumbing
  perfect progressive

Etymology

Origin of plumb

1250–1300; Middle English plumbe, probably < Anglo-French *plombe < Vulgar Latin *plumba, for Latin plumbum lead

Explanation

To plumb a body of water, you measure its depth. To plumb a house, you connect all of its pipes. To make carpentry plumb, you get it exactly vertical. Originally, the verb plumb only meant “to measure the depth of water.” These days, if you “plumb the depths” of something, you go in deep for knowledge and experience: your Heidegger seminar may plumb the depths of German Existentialism like Jacques Cousteau plumbed the depths of the ocean.

Example Sentences

See Examples For:

plumb Plumb plumbs plumbed plumbing

An inswinger had Masood plumb lbw and Root celebrated with that child-like enthusiasm from his early England days with both arms high above his head.

From BBC ● Aug. 19, 2026

Perhaps there are investigative pieces to be done here by enterprising Timesfolk willing to plumb the depths of the surveillance they allege is being conducted by their employer.

From The Wall Street Journal ● May 27, 2026

Honestly, it’s refreshing to be repulsed and intrigued by a movie willing to plumb these psychological depths when Hollywood won’t.

From Los Angeles Times ● May 9, 2026

Or maybe we’ll plumb new depths of dysfunction in the coming year.

From Salon ● Dec. 31, 2025

We’d seen him babbling and walking cockeyed down the road, leaning over so far you keep thinking he’ll plumb fall over.

From "The Poisonwood Bible" by Barbara Kingsolver

"I also cannot believe this happened," Plumb wrote on Instagram after sharing pictures of the event showing Spielberg and Domingo surrounded by pub-goers.

From BBC ● Jun. 6, 2026

Even people who say they have medical qualifications are spreading misinformation online and in podcasts, according to psychosexual and relationship therapist Evie Plumb.

From BBC ● Apr. 11, 2026

Plumb and his faculty leaders weighed the cost to run courses against the enrollment and value for students.

From The Wall Street Journal ● Apr. 9, 2026

Plumb championed a new emergency services major that has drawn wide student interest.

From The Wall Street Journal ● Apr. 9, 2026

New Experiments in Grafting, Budding, or Inoculating; whereby all Sorts of Fruit may be much more improv’d than at present; particularly, The Peach, Apricot, Nectarine, Plumb, &c.

From The Memoirs of Charles-Lewis, Baron de Pollnitz, Volume IV Being the Observations He Made in His Late Travels from Prussia thro' Germany, Italy, France, Flanders, Holland, England, &C. in Letters to His Friend. Discovering Not Only the Present State of the Chief Cities and Towns; but the Characters of the Principal Persons at the Several Courts. by Karl Ludwig von P?llnitz

Words can’t really do justice to the profound musical depths Henry plumbs in this searing revival of “Ragtime,” directed by Lear deBessonet for Lincoln Center Theatre.

From Los Angeles Times ● May 5, 2026

Mr. Rowlands plumbs his own most personal and treasured recollections for examples.

From The Wall Street Journal ● Oct. 17, 2025

In keeping with its title, “Choreomaniacs,” which seems to pick up where “Revolver” leaves off, plumbs wilder depths.

From New York Times ● Apr. 24, 2023

Among these some 300 pages are gems, including “Among the Trees,” by poet Carl Phillips, who plumbs the human connections that can be forged in a forest.

From Washington Post ● Apr. 12, 2023

You may make your syrrup red with the juice of red plumbs.

From English Housewifery Exemplified in above Four Hundred and Fifty Receipts Giving Directions for most Parts of Cookery by Elizabeth Moxon

Even though the S&P 500’s dividend yield is on the cusp of breaking below the record low 1% it plumbed at the peak of the dot-com bubble, several stocks are at the other extreme.

From The Wall Street Journal ● May 7, 2026

Under Amorim, United have plumbed depths that should not be possible the way football's finances are arranged these days.

From BBC ● Jan. 5, 2026

For proof of the formula’s resilience, look no further than the success of VH1’s “Behind the Music” series, which plumbed the depths of dozens of rock ’n’ roll train wrecks.

From Los Angeles Times ● Dec. 17, 2025

The Indian currency has plumbed a series of new lows versus its U.S. counterpart over the past months, crossing the key psychological level of 90 on Wednesday.

From The Wall Street Journal ● Dec. 3, 2025

Design specifications required that every building be surrounded by an underwater main and be plumbed with interior standpipes.

From "The Devil in the White City" by Erik Larson

He painted bedrooms, took charge of the block’s recycling efforts and fixed countless plumbing problems.

From Los Angeles Times ● Sep. 8, 2026

The method begins with PVC similar to the material found in household plumbing, window structures, and even credit cards.

From Science Daily ● Aug. 29, 2026

This one responded to a price, not to plumbing, which is exactly how the market read it, and why the effect evaporated within a day.

From The Wall Street Journal ● Aug. 24, 2026

The company saw gains in its plumbing, kitchen and gardening sections.

From MarketWatch ● Aug. 21, 2026

I say, “I don’t know a reason for plumbing pipes to be that big. What you’re showing me is way bigger than the flushing hole of a toilet, Calvin.”

From "The Truth as Told by Mason Buttle" by Leslie Connor

Related Words

• delve
• explore
• fathom
• penetrate
• unravel