Cannabinoids

Cannabinoids are a class of compounds that interact directly with cannabinoid receptors.

There are at least 85 different cannabinoids isolated from cannabis. They belong to the chemical class of terpenophenolics. Antidepressant-like effect of delta9-tetrahydrocannabinol and other cannabinoids isolated from Cannabis sativa L.
El-Alfy AT, Ivey K, Robinson K, Ahmed S, Radwan M, Slade D, Khan I, ElSohly M, Ross S.
Pharmacol Biochem Behav. 2010 Jun;95(4):434-42. doi: 10.1016/j.pbb.2010.03.004. Epub 2010 Mar 21.
PMID: 20332000

The US National Cancer Institute defines:
cannabinoid (kuh-NA-bih-noyd). A type of chemical in marijuana that causes drug-like effects all through the body, including the central nervous system and the immune system. The main active cannabinoid in marijuana is delta-9-tetrahydrocannabinol (THC). Cannabinoids may help treat the symptoms of cancer or the side effects of cancer treatment. cannabinoid
National Cancer Institute Dictionary
716077
(Accessed 4 August 2015)

Further reading:

Cancer and Cannabinoids for Health Professionals. (Cancer.gov).
Information for Health Care Professionals. (Health Canada).
Wikipedia