An agunah or aguna (Hebrew: עגונה \ עֲגוּנָה, aguná, plural: עגונות \ עֲגוּנוֹת, agunót; plural form: agunot; literally "anchored" or "chained") is a Jewish woman who is stuck in her religious marriage as determined by halakha (Jewish law). The classic case of this is a man who has left on a journey and has not returned, or has gone into battle and is missing in action. It is used as a borrowed term to refer to a woman whose husband refuses, or is unable, to grant her a divorce (which requires a document known as a get).
For a divorce to be effective, halakha requires that a man grant his wife a get of his own free will. Without a get, no new marriage will be recognized, and any child she might have with another man would be considered a mamzer (illegitimate). It is sometimes possible for a woman to receive special dispensation from a posek (halakhic authority), called a heter agunah, based on a complex decision supported by substantial evidence that her husband is presumed dead, but this cannot be applied if the husband is clearly alive.
Because of the difficulty for women in such situations, it has been a task for every generation of halakhic authorities to try to find halakhically acceptable means to permit such women to remarry. In the past it was not uncommon, due to the danger of travel and primitive means of communication, for people leaving home never to be heard of again; consequently rabbis often had had to deal with this issue. Over the past few centuries, thousands of responsa have been written to deal with cases of agunot.
In the past most agunah cases were due to a husband dying without leaving clear evidence of his demise, or becoming mentally ill (insane). Nowadays many agunah cases arise as a result of a husband withholding a get, perhaps seeking a more favorable divorce settlement, or out of vindictiveness.[1] In response agunah groups have organized to support these women and try to find a solution to this problem. Various remedies have been proposed, but as yet, no one solution has common acceptance. Nevertheless, the Jewish prenuptial agreement is one remedy which is in use in Modern Orthodox Jewish communities worldwide and is accepted by moderate halakhic authorities.[2][1]