noun

• (historical) In England, formerly, the highest court of judicature next to the Parliament, exercising jurisdiction at law, but chiefly in equity; but under the jurisdiction act of 1873 it became the chancery division of the High Court of Justice, and now exercises jurisdiction only in equity
• (historical) In the Middle Ages, a government office that produced and notarized official documents.
• (boxing, slang) The position of a boxer's head when under his adversary's arm.
  "The Chicken himself attributed this punishment to his having had the misfortune to get into Chancery early in the proceedings, when he was severely fibbed by the Larkey one, and heavily grassed."
• (slang, archaic) Any awkward predicament.

adv

• (boxing) With the head of an antagonist under one's arm, so that one can pommel it with the other fist at will.
  "[Round] 9. This was a scientific round on both sides; Acton got away well; and also parried some tremendous blows. The latter, however, received a chancery nobber; but he contended every inch of ground till he went down."
• (figurative) In an awkward situation; wholly under the power of someone else.