Definition: Apomorphine is a chemical compound found in plants. It's used for pain relief and muscle relaxation. Definition: The process by which a substance transforms a different substance into another, often as a result of being altered or "bottled" from its original source. In this case, 'apomorphine' refers to the chemical compound that is used for pain relief and muscle relaxation. It's a natural, non-toxic, psychoactive compound found in plants.