sealant

From seal +‎ -ant.

• IPA^(key): /ˈsiːlənt/
• Hyphenation: seal‧ant

sealant (countable and uncountable, plural sealants)

1. Any material used to seal a surface so as to prevent passage of a fluid.
2. (construction) A mixture of polymers, fillers, and pigments used to fill and seal joints where moderate movement is expected.