pris·on·er 
(prĭzə-nər, prĭznər)
(prĭzə-nər, prĭznər)n.
Idiom: 1. A person held in custody, captivity, or a condition of forcible restraint, especially while on trial or serving a prison sentence.
2. One deprived of freedom of expression or action: "He was a prisoner of his own personality—of that given set of traits that ... predisposed him to see the world in a certain way, to make certain moves, certain choices" (William H. Hallahan).
take no prisoners
1. To kill all of an enemy or a population.
2. To be ruthless or unrestrained, as in an undertaking: "Grandmother was both very pretty and very mouthy. She took no prisoners" (Nicki Giovanni).