What does alkaloid mean?
The definition of alkaloid
Al”ka*loid, n. (Chem.)
An organic base, especially one of a class of substances occurring ready formed in the tissues of plants and the bodies of animals.

Note: Alcaloids all contain nitrogen, carbon, and hydrogen, and many of them also contain oxygen. They include many of the active principles in plants; thus, morphine and narcotine are alkaloids found in opium.