trial court

first court that ruled on a case

A trial court or court of first instance is the court in which most civil or criminal cases begin. Not all cases are heard in trial courts; some cases may begin in inferior limited jurisdiction bodies such as the case of the jurisdiction of an administrative body that has been created by statute to make some kind of binding determination under the law and where simplified procedural practices may apply similar to arbitration.
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Noun
1. the first court before which the facts of a case are decided
(hypernym) court, tribunal, judicature
(classification) law, jurisprudence

The trial court is the court in which a lawsuit is filed, and where all litigation up to and including the trial is held.