1.An engraved or inscribed stamp, used for marking an impression in wax or other soft substance, to be attached to a document, or otherwise used by way of authentication or security.
2.Wax, wafer, or other tenacious substance, set to an instrument, and impressed or stamped with a seal; as, to give a deed under hand and seal. "Till thou canst rail the seal from off my bond Thou but offend'st thy lungs to speak so loud."
3.That which seals or fastens; esp., the wax or wafer placed on a letter or other closed paper, etc., to fasten it.
4.That which confirms, ratifies, or makes stable; that which authenticates; that which secures; assurance. "Under the seal of silence." "Like a red seal is the setting sun On the good and the evil men have done."
5.An arrangement for preventing the entrance or return of gas or air into a pipe, by which the open end of the pipe dips beneath the surface of water or other liquid, or a deep bend or sag in the pipe is filled with the liquid; a draintrap.
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