cruel and unusual punishment
noun
: punishment that is very harsh and too severe for the crime
The law forbids cruel and unusual punishment.
Legal Definition
cruel and unusual punishment
noun
cruel and un·usu·al punishment
: punishment that is offensive to the contemporary morality or jurisprudence (as by being degrading, inflicting unnecessary and intentional pain, or being disproportionate to the offense)
nor cruel and unusual punishments inflicted 
U.S. Constitution amend. VIII
see also Gregg v. Georgia compare corporal punishment, death penalty U.S. Constitution amend. VIIINote: A cruel and unusual punishment is essentially one that the courts consider to violate the Eighth Amendment based on a variety of criteria. The interpretation of what constitutes cruel and unusual punishment has changed over time and has varied from jurisdiction to jurisdiction. Most forms of corporal punishment formerly used at common law have been found to be cruel and unusual punishments.