Counsel
The Cyclopedic Law Dictionary · Walter A. Shumaker and George Foster Longsdorf; ed. James C. Cahill · 1922
The Cyclopedic Law Dictionary
The counsellors who are associated in the management of a particular cause, or who act as legal advisers in reference to any matter requiring legal knowledge and judgment. The term is used both as a singular and plural noun, to denote one or more, though it is perhaps more common, when speaking of one of several counsellors concerned in the management of a case in court, to say that he is "of counsel."
Knowledge.
A grand jury is sworn to keep secret "the commonwealth's counsel, their fellows', and their own."