caulk

American  

[kawk] / kɔk /

Or calk

verb (used with object)

• caulks,
  present (3rd person singular)
• caulked,
  past participle,  past
• caulking
  present participle

1. to fill or close seams or crevices of (a tank, window, etc.) in order to make watertight, airtight, etc.

2. to make (a vessel) watertight by filling the seams between the planks with oakum or other material driven snug.

3. to fill or close (a seam, joint, etc.), as in a boat.

4. to drive the edges of (plating) together to prevent leakage.

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noun

1. Also caulking a material or substance used for caulking.

caulk British  

/ kɔːk /

verb

1. to stop up (cracks, crevices, etc) with a filler

2. nautical to pack (the seams) between the planks of the bottom of (a vessel) with waterproof material to prevent leakage

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Other Word Forms

Derived Forms

• caulker
  noun

Inflected Forms

Participles

• caulking
  present
• caulked
  past

Conjugated Forms

Present

• caulk
  simple
• caulks
  simple
• have caulked
  perfect
• has caulked
  perfect
• am caulking
  progressive
• are caulking
  progressive
• is caulking
  progressive
• have been caulking
  perfect progressive
• has been caulking
  perfect progressive

Past

• caulked
  simple
• had caulked
  perfect
• was caulking
  progressive
• were caulking
  progressive
• had been caulking
  perfect progressive

Future

• will caulk
  simple
• will have caulked
  perfect
• will be caulking
  progressive
• will have been caulking
  perfect progressive

Etymology

Origin of caulk

First recorded in 1350–1400; from Latin calcāre “to trample, tread on” (verb derivative of calx “heel”), conflated with Middle English cauken, from Old French cauquer “to trample,” from Latin calcāre, as above

Explanation

Caulk is a sealant. It comes in a tube and is used commonly by plumbers and carpenters trying to seal up cracks where air or water might push through. When a plumber caulks a tub, he's applying caulk to its seams to make it watertight. Caulk can be used to describe both the process of applying caulk and the sealant itself. The word caulk comes from the Old Northern French cauquer, meaning "to press down." After you lay the caulk down over the seam you press it down by either running your finger over it or using a specific tool to force the caulk to settle into the hole you're trying to cover.

Example Sentences

See Examples For:

caulk caulks caulked caulking

To answer those questions, the research team examined previously unstudied materials recovered with the vessel, including cordage and waterproofing caulk.

From Science Daily ● Feb. 16, 2026

Radiocarbon testing of the cordage and caulk indicates the boat was built between the 4th and 3rd centuries BCE.

From Science Daily ● Feb. 16, 2026

“They would come in and put some caulk on it,” he said.

From Seattle Times ● May 28, 2023

Expanding foam sealant, weather-stripping and caulk are excellent solutions for many such problems.

From Seattle Times ● Apr. 19, 2023

Arturo tried to smooth caulk into the crevices, but the caulk cracked when it dried.

From "The Book of Unknown Americans" by Cristina Henríquez

Two of the chemicals released through the burst pipe were butyl acrylate and ethyl acrylate, both colorless liquids with an acrid odor that are used for making paints, caulks and adhesives.

From New York Times ● Mar. 26, 2023

Butyl acrylate is a colorless liquid with a sharp odor used in paints, caulks, sealants and adhesives.

From Salon ● Feb. 15, 2023

There are special caulks meant to seal the seams in aluminum gutters; they’re available online.

From Washington Post ● Apr. 18, 2017

Team name As mentioned previously, this team is backed by the Belgian National Lottery and a major European provider of silicone and caulks, Polyurethane-Foams and adhesives.

From The Guardian ● Jul. 1, 2015

Just as Orde came tramping up the trail, one of the rivermen's caulks failed to "bite" on an unusually smooth, barked surface.

From The Riverman by Stewart Edward White

ICE also said it rushed to make repairs to broken plumbing, caulked all windows and cleaned mold from vents.

From Washington Times ● Jul. 6, 2022

But then, in unexpected circumstances, my caulked tear ducts began springing leaks.

From Washington Post ● Dec. 30, 2021

He added weatherstripping on windows and doors, caulked cracks, put plastic sheets over some windows, switched to LED and CFL bulbs and closed the gap in a basement door.

From Seattle Times ● Nov. 8, 2018

The poop deck is being repaired traditionally, using wooden planks caulked with cotton and oakum then sealed with pitch.

From New York Times ● May 29, 2016

He filled the seams between the new planks with wool yarn unraveled from a scarf and then caulked them with Marston’s oil paints.

From "Shipwreck at the Bottom of the World" by Jennifer Armstrong

Seal up air leaks: Inexpensive weatherstripping and caulking around leaky doors and windows stop hot air from seeping in and forcing your AC to run longer.

From MarketWatch ● Jun. 29, 2026

One of the most striking discoveries was a partial human fingerprint preserved in the caulking.

From Science Daily ● Feb. 16, 2026

Fill the body with a firm, buttery dough—like the decadent chocolate one in our recipe below—and pump the handle like a caulking gun until your baking sheets are festooned with festive flowers, stars and more.

From The Wall Street Journal ● Dec. 5, 2025

They had several commercial uses, including in transformers and capacitors, oil used in motors and hydraulic systems, cable insulation, oil-based paint, caulking and plastics.

From Los Angeles Times ● Sep. 25, 2024

Nat added more notes—this time about caulking a ship.

From "Carry On, Mr. Bowditch" by Jean Lee Latham

Related Words

• block
• shut
• shutter