sole custody; sole parental authority
Legal term referring to a situation where only one parent holds custody and parental rights over a child, as opposed to joint custody.
After the divorce, the mother was granted sole custody.
In Japan, sole custody is common, but the introduction of joint custody is being discussed.
Joint custody, where both parents share parental rights and responsibilities. 単独親権 is the opposite, with only one parent holding authority.
Compound of 単独 (sole, single) and 親権 (parental authority). The term is a modern legal construct.