n. pl. e·col·o·gies
a. The science of the relationships between organisms and their environments.
b. The relationship between organisms and their environment.
2. See human ecology.
[German Ökologie : Greek oikos, house; see weik-1 in the Appendix of Indo-European roots + German -logie, study (from Greek -logiā, -logy).]
ec′o·logi·cal (ĕk′ə-lŏjĭ-kəl, ē′kə-), ec′o·logic (-ĭk) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.