Queen's evidence is a term used in criminal law to describe testimony given by an accomplice of a crime in exchange for a lighter sentence or immunity from prosecution. Other synonyms for this phrase include "crown evidence," "state's evidence," and "government witness." In some jurisdictions, the term "approver's evidence" is used instead. This type of evidence is highly valued by prosecutors, as it can provide crucial information that may lead to the conviction of other individuals involved in the crime. However, it is important to note that the credibility of such testimony is often called into question due to the potential biases of the witness.