privy seal

1 :  a private seal: such as a :  a British royal seal used before 1885 to authorize use of the great seal (as on letters patent or pardons) or on documents not requiring the great seal (as discharges of debts) b :  a seal used in Scotland to authenticate royal grants of personal or assignable rights

2 :  a document bearing a privy seal; especially :  a warrant used by English monarchs in Stuart and earlier periods to exact a forced loan

3 usually capitalized P&S :  lord privy seal