Guillotine Definition: A machine designed to inflict capital punishment by dropping a blade onto the neck, thus quickly severing of the head from the body. A form of capital punishment by using a device called a "guillotine" after its inventor (Joseph Guillotin), developed in France, to "humanely" inflict the death penalty through instant decapitation by the dropping of a weighted and sharp metal blade onto the restrained neck of a convict. Categories & Topics: Criminal Law Dictionary Find you are constantly looking up definitions? Try our search provider (works in most modern browsers) If you find an error or omission in Duhaime's Legal Dictionary, or if you have legal term suggestion, we'd love to hear from you!