Definition of 'Guardian'
An individual who has been given the legal responsibility to care for a child or adult who does not have the capacity for self care. The appointed individual is often responsible for both the care of the ward (the child or incapable adult) and that person's affairs.
Also referred to as a "conservator" when referring to an adult in need of care.
Investopedia explains 'Guardian'
The guardian is usually either named or appointed in a will or in a court of law by a judge. A parent will often name a guardian to his or her children in the event of the parent's death or inability to provide for the children.