A court process to declare that the parties were never legally married to begin with, because at the time of the marriage something was so wrong that no legal relationship could be established by marriage. The annulment decree will specify the legal reason why the marriage was void from the beginning, and will also specify everything else like child custody, parent-child access (visitation), child support, division of property and debt, Spousal maintenance (alimony) and name change of either party if requested. If you are interested in an or annulment, you can get help from an attorney who can get you on the right track to help yourself.
Source: Superior Court of Arizona, Maricopa County
A legal action that says your marriage was never legally valid because of unsound mind, incest, bigamy, being too young to consent, fraud, force, or physical incapacity.
Source: California Courts.