Patent

A grant of some privilege, property, or authority, made by the government or sovereign of a country to one or more individuals.

Phil. Pat. 1.

As the term was originally used in England, it signified certain written instruments emanating from the king, and sealed with the great seal. These instruments conferred grants of lands, honors, or franchises; they were called "letters patent," from being delivered open, and by way of contradistinction from instruments like the French lettres de cachet, which went out sealed. In the United States the word "patent" is sometimes understood to mean the title deed by which a government, either state or federal, conveys its lands. But in its more usual acceptation it is understood as referring to those instruments by which the United States secures to inventors _ for a limited time the exclusive use of their own inventions.