Sasine in Scots law is the delivery of feudal property, typically land.
Feudal property means immovable property, and includes everything that naturally goes with the property. For land, that would include such things as buildings, trees, and underground minerals. A superior (e.g., a heritor) might authorise his agent or factor to give possession of his property to someone else through a document known as a "precept of sasine". One of the earliest records in Scotland is from 1248 when Sir Malcolm, son of the then Earl of Lennox, ‘conferred full Sasine’ of certain lands at Strathblane to Sir David Graham.[1][2]
Over time, sasine came to be used in common speech as a reference to the deed or document recording the transfer, rather than to the transfer itself. Hence phrases such as "to give sasines", "to deliver sasines", "to receive sasines", "to take sasines".
Alternative spellings include: seizin, seisin, sasin, seasin, sasing, seasing, sesin, seasin, sesine, seasine, saisine.[3][4][5]