parole (n.)youdaoicibaDictYouDict
1610s, "word of honor," especially "promise by a prisoner of war not to escape," from French parole "word, speech" (in parole d'honneur "word of honor") from Vulgar Latin *paraula "speech, discourse," from Latin parabola (see parable). Sense of "conditional release of a prisoner before full term" is first attested 1908 in criminal slang.
POW (n.)youdaoicibaDictYouDict
also P.O.W., initialism (acronym) for prisoner of war, coined 1919 but not common until World War II.
prisoner (n.)youdaoicibaDictYouDict
"person in prison, captive person," late 14c. (earlier "a jailer," mid-13c., but this did not survive Middle English), from Old French prisonier "captive, hostage" (12c., Modern French prisonnier), from prisoun (see prison (n.)). Captives taken in war have been called prisoners since mid-14c.; phrase prisoner of war dates from 1670s (see also POW). Prisoner's dilemma attested from 1957.