PLEGIIS ACQUIETANDIS, WRIT DE. The name of an ancient writ in the English law, which lies where a man becomes pledge or surety for another to pay a certain sum of money at a certain day; after the day, if the debtor does not pay the debt, and the. surety be compelled to pay, he shall have this writ to compel the debtor to pay the same. F. N. B. 321.