sealer

/ˈsiːlər/
noun
  1. A substance or product used to coat a surface and make it waterproof or airtight.
    • Before painting the wall, apply a sealer to prevent stains from bleeding through.
    • The driveway was treated with a concrete sealer to protect it from winter weather.
    • I used a wood sealer on the fence to keep it from rotting.
  2. A device or tool that closes and fastens something, such as a bag or container.
    • The vacuum sealer kept the food fresh for weeks.
    • She used a heat sealer to close the plastic packaging.
    • The bag sealer made it easy to store snacks.
Synonyms