De Peyster Divorce & Family Law Lawyer, New York

The inability of a spouse to engage in sexual intercourse with the other spouse. In some states, physical incapacity is a ground for an annulment or fault divorce, assuming the incapacity was not disclosed to the other spouse before the marriage.

A tradition that required one spouse to prove that the other spouse was legally at fault, to obtain a divorce. The 'innocent' spouse was then granted the divorce from the 'guilty' spouse. Today, 35 states still allow a spouse to allege fault in obtaining a divorce. The traditional fault grounds for divorce are adultery, cruelty, desertion, confinement in prison, physical incapacity and incurable insanity. These grounds are also generally referred to as marital misconduct.

A person who supports and maintains, in one household, one or more people who are closely related to him by blood, marriage or adoption. Under federal income tax law, you are eligible for favorable tax treatment as the head of household only if you are unmarried and you manage a household which is the principal residence (for more than half of the year) of dependent children or other dependent relatives. Under bankruptcy homestead and exemption laws, the terms householder and 'head of household' mean the same thing. Examples include a single woman supporting her disabled sister and her own children or a bachelor supporting his parents. Many states consider a single person supporting only himself to be a head of household as well.

An arrangement by which parents who do not live together share the upbringing of a child. Joint custody can be joint legal custody (in which both parents have a say in decisions affecting the child) joint physical custody (in which the child spends a significant amount of time with both parents) or, very rarely, both.

A divorce automatically granted by a court when the spouse who is served with a summons and complaint for divorce fails to file a formal response with the court. Many divorces proceed this way when the spouses have worked everything out and there's no reason for both to go to court -- and pay the court costs.

Latin for 'friend of the court.' This term describes a person or organization that is not a party to a lawsuit as plaintiff or defendant but that has a strong interest in the case and wants to get its two cents in. For example, the ACLU often submits materials to support a person who claims a violation of civil rights even though that person is represented by a lawyer.