1. a substance used to seal or close something to prevent leakage
2. a person or ship engaged in hunting seals
3. a device or tool used to seal containers or packages

Examples

• Apply wood sealer to protect the deck from moisture.
• The concrete sealer prevented water from penetrating the foundation.
• The old sealer returned from months at sea with a full cargo.
• Commercial sealers hunted in the Arctic waters.
• Use a bag sealer to keep food fresh longer.
• The envelope sealer made quick work of the mailing task.
• This grout sealer will prevent stains in your bathroom tiles.