sealer

noun

1. a kind of sealing material that is used to form a hard coating on a porous surface (as a coat of paint or varnish used to size a surface)

   noun.substance

   Synonyms sealant

   Source: WordNet 3.0

2. an official who affixes a seal to a document

   noun.person

   Source: WordNet 3.0

3. One who seals; especially, an officer whose duty it is to seal writs or instruments, to stamp weights and measures, or the like.

   noun

   Source: webster1913

4. A mariner or a vessel engaged in the business of capturing seals.

   noun

   Source: webster1913