What is Widow?

Legal Definition
A widow is a woman whose spouse has died, while a widower is a man in that situation. The state of having lost one's spouse to death is termed widowhood. These terms are not applied to a person after he or she becomes divorced from their former spouse, though they may sometimes be used after the former spouse has died.

The term widowhood can be used for either sex, at least according to some dictionaries, but the word widowerhood is also listed in some dictionaries. Occasionally, the word viduity is used. The adjective form for either sex is widowed.

The treatment of widows around the world varies, but unequal benefits and treatment generally received by widows compared to those received by widowers globally has spurred an interest in the issue by human rights activists.

When the death of a spouse occurs, it is said that a widowhood effect is to arise. This is a phenomenon that refers to the increased mortality rate after the death of a spouse. It is “strongest during the first three months after a spouse's death, when they had a 66-percent increased chance of dying” (Jegtvig 2013). Most widows and widowers suffer from this effect during the first 3 months of their spouse's death, however they can also suffer from this effect later on in their life for much longer than 3 months. There remains controversy over whether women or men have worse effects from becoming widowed, and studies have attempted to make their case for which side is worse off, while other studies try to show that there are no true differences based on gender and other factors are responsible for any differences.
-- Wikipedia
Legal Definition
An unmarried woman whose husband is dead.

2. In legal writings, widow is an addition given to a woman who is unmarried and whose husband is dead. The addition of spinster is given to a woman who never was married. Lovel. on Wills, 269. See Addition. As to the rights of a widow, seq Dower.
-- Bouviers Law Dictionary
Legal Definition
A woman whose husband is dead, and who has not married again. The "king's widow" was one whose deceased husband had been the king's tenant in capite; she could not marry again without the royal permission.
See also
-- Black's Law Dictionary
Legal Definition
A woman who has lost her husband by death and has not remarried. See 13 Mise. Rep. (N. Y.) 480, 35 N. Y. Supp. 481. See, also, Bang’s widow.
-- Ballentine's Law Dictionary
Legal Definition
A woman whose husband has died during the course of their marriage.