What does sealant mean?
A sealant is a substance used to close, fill, or protect gaps and joints. It is commonly applied as a liquid or paste and then allowed to harden, forming a barrier against water, air, dust, or noise. Sealants appear in products such as tubes, cartridges, and pots, and are used in construction, home improvement, automotive maintenance, and dentistry. The word is more specific than 'filler,' since it describes a product intended to seal rather than merely fill a space. It is also related to, but distinct from, a 'seal,' which is the closure or barrier formed. The choice of sealant depends on the material being treated and the conditions it must withstand, such as moisture, temperature changes, movement, or exposure to weather.
nounA substance used to fill, seal, or protect gaps, joints, or surfaces. Sealants may be flexible, waterproof, weather-resistant, or designed to harden after application.
- A liquid, paste, or similar substance used to fill and close gaps, joints, or cracks.
- A coating or material used to protect a surface by making it impervious to water, air, or other substances.
"The contractor applied sealant around the edge of the window before painting."
"A bead of sealant along the bathtub prevents water from reaching the wall."
"The old roof was repaired with a flexible waterproof sealant."
The plural is used when referring to multiple products, types, or applications of sealant.
"The hardware store stocks several types of sealants for bathrooms and kitchens."
Sealants turn invisible gaps into reliable barriers: a thin line of the right compound can keep water, air, dust, and sound out.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Words that share this root
Related word forms
How sealant is actually used
Sealant is usually a countable noun when referring to a particular product or application, as in 'a tube of sealant,' and can also be used collectively as an uncountable noun for the material. The term is especially common in construction, automotive work, home repair, and dentistry.
Easily confused with sealant
A sealant is the material used to close a gap, while a seal is the joint, barrier, or closure that it creates.
Sealant is a general term for a material used to prevent leaks or close gaps, whereas caulk often refers specifically to a sealing compound used in joints and seams.