M'Naghten test

[muh k-nawt-n]

noun

a rule that defines a person as legally insane when that person cannot distinguish right from wrong.

Origin of M'Naghten test

after Daniel M'Naghten (died 1865), defendant in a murder case adjudicated in England in 1843
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019