Not the same as hostile arguing, giving a speech, or simply repeating questions asked by the other side. It is the stage of testimony in which one party questions a witness called by the opposing party, usually to test accuracy, expose inconsistency, show bias, or limit the force of the witness's statements. In court, it follows direct examination and is generally confined to the subjects raised on direct examination and matters affecting the witness's credibility, though a judge may allow a broader inquiry.

Practically, cross-examination is where a case's weak points are often exposed. A witness may be confronted with prior statements, medical records, photographs, deposition testimony, or gaps in memory. In an injury case, that can affect how a jury views pain complaints, the timing of symptoms, the severity of a concussion or other traumatic brain injury, and whether treatment was connected to the incident at issue rather than a prior condition.

In Massachusetts, cross-examination can directly affect fault allocation and damages. Under the Commonwealth's modified comparative negligence rule, Massachusetts General Laws chapter 231, section 85 (1969), a plaintiff cannot recover if found more than 50 percent at fault. That makes cross-examination especially significant when the defense tries to show inconsistent conduct, delayed treatment, or alternative causes of injury after a crash, fall, or storm-related event.