A defendant refers to a person or entity that is accused of a crime in a criminal prosecution or a person or entity against whom some type of civil relief is being sought. In every criminal or civil case there is both a plaintiff and a defendant. In some instances, there may be more than one plaintiff or defendant.
If a person or entity is being sued by his or her neighbor for a trespass lawsuit, for example, he or she is the defendant in a civil suit. Likewise, the person who is being accused of murder by the state in a capital murder case is the defendant in this criminal action. If a defendant loses his or her case at the trial court level and decides to appeal, he or she will then be referred to as the appellant. If the plaintiff is the one who appeals the case, then the defendant will be referred to as the appellee.