One who holds that there must be retribution (vengeance, punishment) for transgressions.(noun)
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Use "retributionist" in a sentence
"It cuts against our retributionist instincts, but holds out the promise of achieving crime reduction while also having less recourse to prison."
"Labor's Lost Love: The Obama White House was afraid to directly confront the labor unions 'retributionist drive to oust Lincoln in favor of Lt. Gov."
"But, to be honest, few things make me start to reconsider that opinion more than the naked retributionist opinions that appear whenever the death penalty is discussed in certain forums."