What is "abstention doctrine"

n. (context legal English): A rule under which a federal court in the United States will decline to exercise jurisdiction over a lawsuit because the suit could or should instead be heard by a state court.

An abstention doctrine is any of several doctrines that a court of law in the United States of America may (or in some cases must) apply to refuse to hear a case if hearing the case would potentially intrude upon the powers of another court. Such doctrines are usually invoked where lawsuits involving the same issues are brought in two different court systems at the same time (such as federal and state courts within a federal system).

The United States has a federal court system with limitations on the cases that federal courts can hear, while each state has its own individual court system. In some instances, the jurisdiction of these courts overlap, so a lawsuit between two parties may be brought in either or both courts. The latter circumstance can lead to confusion, waste of resources, as well as the appearance that one court is disrespecting the other. Both federal and state courts have developed rules determining when one court will defer to another's jurisdiction over a particular case.