prisoner
prisoner of conscience a person detained or imprisoned because of their religious or political beliefs.
☞ This phrase is particularly associated with the campaigns of Amnesty International, a human-rights organization.
take no prisoners be ruthlessly aggressive or uncompromising in the pursuit of your objectives.
2012New York Times Beyond nudity and yelling, 'common ingredients in performance art', the reputation of Ann Liv Young is that she is ruthless, shameless and takes no prisoners.