Cruel and Unusual Punishment Definition

A punishment that is extremely excessive in relation to the crime, shocking to ordinary sensibilities, or equivalent to torture. Cruel and unusual punishment is prohibited, but not defined, by the Eighth Amendment to the U.S. Constitution.

The definition of cruel and unusual punishment has changed over the years, as the courts have responded to "evolving standards of decency." (Trop v. Dulles, 356 U.S. 86 (1958)). Death penalty cases frequently take up the issue of cruel and unusual punishment. There is still much debate about whether certain methods of carrying out the death penalty, including lethal injection, violate the Eighth Amendment.

For more detail, see The Meaning of "Cruel and Unusual Punishment".