What is Alternative Writ?

Legal Definition
A writ commanding the person against whom it is issued to do a specified thing, or show cause to the court why he should not be compelled to do it. Allee v. McCoy, 2 Marv. (Del.) 465, 36 Atl. 359.
-- Black's Law Dictionary
Legal Definition
One commanding a party to do or cease doing something or show cause why he has not. See 71 Conn. 381, 42 Atl. 82.
-- Ballentine's Law Dictionary