a notable achievement; "he performed a great deed"; "the book was her finest effort"
a legal document signed and sealed and delivered to effect a transfer of property and to show the legal right to possess it; "he signed the deed"; "he kept the title to his car in the glove compartment"
based on custom rather than documentation; "an unwritten law"; "rites...so ancient that they well might have had their unwritten origins in Aurignacian times"- J.L.T.C.Spence