pris·on·er n: a person deprived of liberty and kept under involuntary restraint, confinement, or custody; esp: one under arrest, awaiting trial, on trial, or serving a prison sentence
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.
captive, confined individual, convict, criminal, detainee, felon, hostage, incarcerated person, individual held in custody, individual jailed, inmate, internee, jailed person, person under arrest
captive, convict, hostage, inmate
Burton's Legal Thesaurus. William C. Burton. 2006
n.A person confined to a prison; a person confined against his or her will.
The Essential Law Dictionary. — Sphinx Publishing, An imprint of Sourcebooks, Inc. Amy Hackney Blackwell. 2008.