III. Vows of Chastity.
A lady, after her husband's death, was allowed to take the vow of chastity, and she was then called a vowess. A kind of investiture took place, generally, I believe, during or before the celebration of mass, when the officiator gave the vowess a pall or mantle, a veil, and a ring, and she then made a vow of chastity in a set form of words. The celebrant was not necessarily a Bishop, but an Abbat or a Prior might act in his stead. This vow merely obliged the lady to live in chastity. She was not severed from the world, but could live in it and make a will, and dispose of her property as she chose. We sometimes find that the vowess, for the sake of a stricter and a more retired life, took up her abode in or near some monastery, particularly a nunnery. She was, however, merely a lodger, or, to use the old term, a perhendinaria. I have given many examples of the vows that were taken by these ladies. The whole subject opens out a new phase of mediaeval life.
James Raine (1865) Testamenta Eboracensia; a Selection of Wills from the Registry at York, vol. III, Publications of the Surtees Society, p. 312.