Writ of Extent:

“A writ issued by the Exchequer to recover a debt owed to the Crown, under which the debtor s lands, goods, or body could all be seized to secure payment.”

Definition of Extent:

“(16c.) Hist. A seizure of property in execution of a writ.”

• Extent in Chief: “(18c) A writ of extent issued at the suit of the Crown.”
• Extent in Chief in the Second Degree: “(1835) A writ of extent issued against a
  debtor of a Crown debtor, so that it resembles a garnishment. See
  GARNISHMENT.”
• Immediate Extent: “(18c.) A writ of extent issued without a commission of
  inquest or a scire facias.”

3. A writ giving a creditor temporary possession debtor’s property (especially land). – Also termed extendi facias.”

References:

[1]: Black’s Law Dictionary Deluxe Tenth Edition by Henry Campbell Black & Editor in Chief Bryan A. Garner. ISBN: 978-0-314-62130-6