From Longman Dictionary of Contemporary Englishsealerseal‧er /ˈsiːlə $ -ər/ noun 1 [countable, uncountable]TD a substance that is put on the surface of something to protect it from air, water etc2 [countable]TTW a person or ship that hunts seals
Examples from the Corpus
sealer• Wrap pressure-treated wood with heavy plastic, or coat it with a sealer.• So buy the best sealer you can find, and use it faithfully.• The multimedia part offers animated information about design considerations and follows through all the way to applying deck sealer and making repairs.• To remain effective, sealers must be renewed, usually every year or two.• Then seal all the edges with a ribbon of sealer to make them watertight.• Seal all tent seams with seam sealer. 3.• The old sides can be removed by slicing through the silicone sealer with a razor or scalpel.• The same goes for diving in front of a seal pup to protect it from the sealers. 