1. The science of life and of living organisms, including their structure, function, growth, origin, evolution, and distribution and encompassing numerous fields such as botany, zoology, mycology, and microbiology.
2. The life processes or characteristic phenomena of a group or category of living organisms: the biology of fungi.
3. The living organisms present in a specific area or region.
[German Biologie : Greek bio-, bio- + Greek -logiā, -logy.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.