A formal declaration , complaint, or statement of particular things in writing. As a legal term, this word has many meanings and applications, the more important of which are enumerated below. 1. A formal written statement of complaint to a court of justice. In the ancient practice of the court of king’s bench, the usual and orderly method of beginning an action was by a bill, or original bill , or plaint. This was a written statement of the plaintiff’s cause of action , like a declaration or complaint, and always alleged a trespass as the ground of it, in order to give the court jurisdiction . 3 Bl. Comm. 43. In Scotch law , every summary application in writing, by way of petition to the Court of Session , is called a “bill.” Cent. Diet.