A written agreement; a bond; a deed; a promise not to do something. [Mitra’s Legal & Commercial Dictionary]

A written obligation or agreement, a bond, a deed, it is commonly applied to a covenant on the part covenant on the part of the cultivators of land, agreeing to the rates of assessment or rent; also to an engagement under a penalty to observe the conditions of any deed or grant, or to one exacted from thieves or suspected persons engaging to desist or refrain from any illegal acts; or to one from superior police or other officers engaging to be responsible for the conduct of the subordinates appointed by themselves, or to any penal recognizance which may be required by a Magistrate. [Wilson’s Glossary]