What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
1Law a clause in a legal document reserving the right of certain parties to alter or repeal the terms of the document.
2Sport a clause in a professional player's contract with a team, reserving the team's rights to the player once the contract has expired, preventing free movement between teams (now chiefly historical).
Mid 19th century.