The process of slaughter entails taking an animal's life, most commonly by the slitting of the individual's throat while forcibly held in an upside down position in order to facilitate the draining of the blood prior to skinning and dismemberment. According to the American Heritage Dictionary, the definition of "Humane" includes such words as compassionate and merciful. To have one's throat involuntarily slit may be many things, but few on the receiving end of such an act would be likely to call it merciful, or compassionate. Hence, humane slaughter is an oxymoron.
Common Misuse: Both the animal-using industry and some animal advocates make use of this term to refer to methods of slaughter that are claimed to somehow be better than others, such as those that attempt to render the animal unconscious before they are killed, which theoretically minimizes the pain experienced while still leaving the heart beating in order to forcefully push out the blood. While the use of such methods clearly improve the efficiency and speed of slaughterhouse operations, it is not possible to claim that either mercy or compassion are being practiced during any act of taking another's life for the purposes of profit.