caulk
6 synonyms and 0 antonyms for caulk, grouped by meaning and by how common each one is.
Noun — A flexible waterproof filler squeezed into joints and gaps — around baths, sinks, window frames and skirting boards — to seal them against water and draughts.
Synonyms
Everyday swaps
Common words most readers know — safe in any writing.
Less common
Still standard English, but they carry more weight.
Rare, literary or technical
Precise, but they will stand out — check the sense before using one.
Synonyms by Meaning
1. noun
A flexible waterproof filler squeezed into joints and gaps — around baths, sinks, window frames and skirting boards — to seal them against water and draughts.
“Run a bead of caulk along the edge where the bath meets the tiles.”
2. verb
To seal a joint or gap by filling it with such a compound.
“Caulk around the window frame before you paint it.”
How to use caulk
The word patterns that sound natural to a native speaker.
Neutral. Everyday in DIY and trade contexts; the noun is more common in American English than British, where sealant dominates.
Etymology
From Old North French cauquer, from Latin calcare 'to tread or press down', reflecting the original sense of pressing material into a ship's seams.
Full origin of caulk →Frequently asked questions
What is the difference between caulk and silicone?
Silicone is one type of caulk, not a rival product. Caulk is the general word for a gap-filling sealant; silicone caulk stays flexible and waterproof so it suits baths and showers, while acrylic or latex caulk can be painted over and suits skirting boards and trim.
Is caulk spelled differently in Britain?
Both caulk and calk appear historically, but caulk is now standard everywhere. In British usage the product is just as often called sealant or mastic, and the tube is bought as bathroom sealant rather than caulk.
How is caulk pronounced?
It rhymes with talk and walk — the L is silent. Saying it as kalk is a common misreading.