zo·ol·o·gy (zō-ŏlə-jē, z-)
n. pl. zo·ol·o·gies
1. The branch of biology that deals with animals and animal life, including the study of the structure, physiology, development, and classification of animals.
2. The animal life of a particular area or period: the zoology of Alaska; the zoology of the Pleistocene.
3. The characteristics of a particular animal group or category: the zoology of mammals.
4. A book or scholarly work on zoology.
Usage Note: Traditionally, the first syllable of zoology has been pronounced as (zō), rhyming with toe. However, most likely due to the familiarity of the word zoo (which is merely a shortened form of zoological garden), the pronunciation of the first syllable as (z) is also commonly heard. In our 2017 survey, 89 percent of the Usage Panel found the (zō-) pronunciation acceptable and 72 percent found the (z-) pronunciation acceptable. Also, 55 percent reported using the (zō-) pronunciation and 45 percent using the (z-) pronunciation in their own speech. While both pronunciations are acceptable, the (zō-) pronunciation may be perceived as more scientific.
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.