There are several synonyms for the term "illegal detention" which refers to the unlawful confinement of a person. Some of these synonyms include wrongful imprisonment, unlawful incarceration, illegal custody, and false imprisonment. These terms denote the same concept of restricting someone's freedom without legal authority or justification. Illegal detention may occur in various situations such as police custody, prisons, and even in private settings. It is a violation of human rights and is punished under the law. The use of these synonyms helps to clarify and emphasize the gravity of this offense and the need to prevent it from happening in any circumstance.