A motion to strike is a legal motion

Motion (legal)

In law, a motion is a procedural device to bring a limited, contested issue before a court for decision. A motion may be thought of as a request to the judge to make a decision about the case. Motions may be made at any point in administrative, criminal or civil proceedings, although that right is...

 given by one party in a trial requesting the presiding judge order the removal of all or part of the opposing party's pleading

Pleading

In law as practiced in countries that follow the English models, a pleading is a formal written statement filed with a court by parties in a civil action, other than a motion...

 to the court. A motion to strike is also used to request elimination of all or part of a trial witness's testimony. During a jury trial

Jury trial

A jury trial is a legal proceeding in which a jury either makes a decision or makes findings of fact which are then applied by a judge...

, if motion to strike witness testimony is accepted, the jury is instructed to disregard the stricken statements.