- Any of a class of nitrogenous organic compounds of plant origin that have pronounced physiological actions on humans. They include many drugs (morphine, quinine) and poisons (atropine, strychnine).More example sentences
- Other important alkaloids are caffeine, ricinine, and quinine.
- Morphine is an alkaloid, meaning that it is an organic compound that contains carbon, hydrogen and nitrogen, and forms a water-soluble salt.
- This material is a complex mixture of about 20 different alkaloids or nitrogen containing organic bases.
early 19th century: coined in German from alkali.
More definitions of alkaloidDefinition of alkaloid in:
- The British & World English dictionary