noun
1. : a guardian by natural relationship having custody of the person but not the property of a minor and under common law being constituted by the father if fit and upon his death or incapacity the mother and in the absence of lawful parents the grandparents or other close relatives
2. : the person who is in fact exercising parental authority over a minor as distinguished from a guardian appointed by a court to have custody of the person or property of the minor — called also guardian by nature ; compare guardian for nurture , guardian in socage