a French word, signifying he or him, frequently used in the English law writings. Thus, Cestui qui trust, a person who has lands, &c., committed to him for the benefit of another; and if such person does not perform his trust, he is compellable to it in chancery. Cestui qui vie, one for whose life any lands, &c., are granted. Cestui qui us, a person to whose use any one is inclosed of lands or tenements. Formerly the feoffees to uses were deemed owners of the land, but now the possession is adjudged in cestui qui us.