Cannabis, also known as marijuana among other names, is a psychoactive drug from the Cannabis plant used for medical or recreational purposes. Cannabis, also known as marijuana among other names, is a psychoactive drug from the Cannabis plant used for medical or recreational purposes. Global spending on legal cannabis is expected to grow 230%, to $31.3% billion in 2022, compared to $9.5 billion in 2017, according to Arcview Market Research and BDS Analytics.