caulk

1 of 3

verb

ˈkȯk 

variants or calk

caulked or calked; caulking or calking; caulks or calks

transitive verb

: to stop up and make tight against leakage (something, such as a boat or its seams, the cracks in a window frame, or the joints of a pipe)

caulker noun

caulk

2 of 3

noun (1)

variants or calk or less commonly caulking or calking

ˈkȯ-kiŋ 

: material used to caulk

caulk

3 of 3

noun (2)

variant spelling of calk entry 2, calk entry 3

: a cleat on the shoe of a horse to prevent slipping

also : a similar device worn on the sole of a shoe

Examples of caulk in a Sentence

Verb

He carefully caulked the area around the windows.

Recent Examples on the Web

Verb

Ole Kastholm, a specialist in ancient Scandinavian seafaring and a senior researcher at the Roskilde Museum in Denmark, found the unexpected use of pine pitch for caulking to be exciting. —Taylor Nicioli, CNN Money, 11 Dec. 2025

Carpenter bee holes may also be caulked to try and discourage further nesting. —Arricca Elin Sansone, Southern Living, 5 Nov. 2025

Noun

Use waterproof caulk or sealant to fill gaps and treat walls with mold-resistant paint or primer. —Ashlyn Needham, Southern Living, 22 Dec. 2025

Homeowners should inspect attics for signs of moisture, drafts or daylight peeking through, and refresh caulk around chimneys or vents. —Brendel Clark, Freep.com, 16 Dec. 2025

Word History

Etymology

Verb

Middle English caulken, from Anglo-French cauker, calcher, chalcher to trample, from Latin calcare, from calc-, calx heel

First Known Use

Verb

15th century, in the meaning defined above

Noun (1)

1954, in the meaning defined above

Rhymes for caulk

• balk
• baulk
• bloc
• bock
• broch
• brock
• calk
• chalk
• chock
• clock
• cock
• croc

Kids Definition

caulk

verb

variants or calk

ˈkȯk

: to fill up a crack, seam, or joint so as to make it watertight

caulker noun