Generally speaking, the definition of a prenuptial, premarital, antenuptial agreement (yes, those are three names for the same thing) is a contract drafted between two soon-to-be spouses that is not effective until marriage. More specifically, a Prenuptial Agreement is again, a legal contract. Generally speaking, a prenup is referred to as a “premarital” agreement in Illinois, although the definition of a prenuptial, premarital and antenuptial agreement are all terms for the same thing.
According to the Illinois Uniform Premarital Agreement Act, effective and adopted by the state of Illinois in 1990, “Premarital agreement” refers to an agreement between prospective spouses made in contemplation of marriage, and is to be effective upon marriage. A premarital agreement in Illinois allows couples to contract with respect to the rights and obligations of property, the right to sell or control property, the ability to choose how they will dispose of property upon separation, dissolution or death, the modification or elimination of spousal support, the ownership rights in a life insurance policy, freedom to choose what law will govern the agreement, as well as other rights as listed in the Illinois Premarital Agreement statute, which you can read here. However, it is important to note that the rights of a child or child support cannot be affected by a premarital agreement in Illinois.