What is Chantry?

Legal Definition
A chantry or obiit (Latin: "he has departed"; may also refer to the mass or masses themselves) was a form of trust fund established during the pre-Reformation medieval era in England for the purpose of employing one or more priests to sing a stipulated number of masses for the benefit of the soul of a specified deceased person, usually the donor who had established the chantry in his will, during a stipulated period of time immediately following his death. It was believed such masses would speed the deceased's soul through its undesirable and indeterminate period in Purgatory onwards to eternal rest in Heaven. Clearly once the soul had reached Heaven the ideal state for the Christian human soul had been attained, and the saying of masses would serve no further function. Thus the concept of Purgatory was central to the perceived need for chantries. Chantries were commonly established in England and were endowed with lands, rents from specified properties and other assets by the donor, usually in his will. The income from these assets maintained the chantry priest.

A chantry chapel is a building on private land or a dedicated area or altar within a parish church or cathedral, set aside or built especially for the performance of the chantry duties by the priest. A chantry may occupy for premises a single altar, for example in the side aisle of a church, rather than an enclosed chapel within a larger church, generally dedicated to the donor's favourite saint. Many such chantry altars became richly endowed, often with gold furnishings and valuable vestments. Over the centuries chantries increased their wealth, often by attracting new donors, and chantry priests, or those feoffees who employed them, were in many cases able to enjoy great wealth. In some instances this led to corruption of the consecrated life expected of clerics. It also led in general to an accumulation of great wealth and power by the Church, beyond the feudal control of the Crown. This evident corruption was one of the factors utilized by King Henry VIII to order the Dissolution of the Monasteries in England. At that time, chantries were abolished and their assets were sold or granted to persons at the discretion of King Henry VIII and his son King Edward VI, via the Court of Augmentations. Many Tudor period businessmen, such as Thomas Bell (1486-1566) of Gloucester, thus acquired chantries as financial investments producing income streams derived from rents, or "unbundled" the assets and sold them piecemeal at a profit.
-- Wikipedia
Legal Definition
A church or chapel endowed with lands for the maintenance of priests to say mass daily for the souls of the donors. Termes de la Ley; Cowell.
-- Black's Law Dictionary