Legal custody
Etymology
From "custody," Latin "custodia" (guarding, safekeeping), from "custos" (guardian). The legal-versus-physical split is a modern family-law refinement, formalized in twentieth-century American statutes as courts began awarding the two independently rather than as one indivisible bundle.
noun phrase · /LEE-guhl KUS-tuh-dee/
The right to make major decisions about a child’s upbringing — schooling, medical care, religion — as opposed to where the child lives day to day.
What it names
It isolates the decision-making half of parenting rights, which courts and parents routinely conflate with the question of the child’s physical location.
Example
They shared legal custody, so even though the kids lived with their mother, both parents had to sign off on the surgery.
Related idea
Distinguish from physical custody, which governs where a child actually sleeps; a parent can hold one without the other, and joint legal custody often coexists with sole physical custody.