from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of various organic compounds normally with basic chemical properties and usually containing at least one nitrogen atom in a heterocyclic ring, occurring chiefly in many vascular plants and some fungi. Many alkaloids, such as nicotine, quinine, cocaine, and morphine, are known for their poisonous or medicinal attributes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of many organic heterocyclic bases, that occur in nature and often have medicinal properties.
- adj. Relating to, resembling, or containing alkali.
from the GNU version of the Collaborative International Dictionary of English
- adj. Pertaining to, resembling, or containing, alkali.
- adj. of or pertaining to alkaloids.
- n. An organic base, especially one of a class of nitrogen-containing substances occurring ready formed in the tissues of plants and the bodies of animals.
from The Century Dictionary and Cyclopedia
- n. A body resembling an alkali in properties; one of a class of nitrogenous compounds which occur in plants in combination with organic acids, and are sometimes called the organic bases of plants, as morphine, nicotine, quinine, etc.
- Relating to or containing alkali.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. natural bases containing nitrogen found in plants
alkal(i) + -oid.(American Heritage® Dictionary of the English Language, Fourth Edition)
alkali + -oid. Compare French alcaloïde. (Wiktionary)