A defendant or defender (Δ in legal shorthand) is any party who is required to answer the complaint of a plaintiff or pursuer in a civil lawsuit before a court, or any party who has been formally charged or accused of violating a criminal statute.
A defendant in a civil action usually makes his or her first court appearance voluntarily in response to a summons, whereas a defendant in a criminal case is often taken into custody by police and brought before a court, pursuant to an arrest warrant. The actions of a defendant, and its lawyer counsel, is known as the defence.
A respondent is the parallel term used in a proceeding which is commenced by petition.
Historically, a defendant in a civil action could also be taken into custody pursuant to a writ of capias ad respondendum and forced to post bail before being released from custody. However, a modern day defendant in a civil action is usually able to avoid most (if not all) court appearances if he or she is represented by a lawyer whereas a defendant in a criminal case (particularly a felony or indictment) is usually obliged to post bail before being released from custody and must be present at every stage thereafter of the proceedings against him or her (they often may have their lawyer appear instead, especially for very minor cases, such as traffic offences in jurisdictions which treat them as crimes). If found guilty, or if the defendant reaches a plea bargain or other settlement with the prosecution, the defendant receives a sentence from the presiding judge. This sentence, however, does not necessarily include the full punishment: social stigma of prosecution and collateral consequences of criminal charges may still affect the defendant.