To get (or to hold) In chancery

(Boxing) to get the head of an antagonist under one's arm, so that one can pommel it with the other fist at will; hence, to have wholly in One's power. The allusion is to the condition of a person involved in the chancery court, where he was helpless, while the lawyers lived upon his estate.

See also: Chancery

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.