from
Bouvier's Law Dictionary, Revised 6th Ed (1856)
PROCESS OF GARNISHMENT, practice. It was formerly the practice to deposit
deeds and other things in the hands of third persons, to await the
performance of covenants, upon which they were to be re-delivered to one of
the parties. When one of the parties contended that he was entitled to such
things, and the other denied it, and the claiming party brought an action of
detinue for them, the defendant was allowed to interplead, and thereupon he
prayed for a monition or notice to compel the other depositor to appear and
become a defendant in his stead. This was called a process of garnishment. 3
Reeves, Hist. Eng. Law, eh. 23, p. 448.