zo·ol·o·gy (z?-?l??-j?, zo?o-)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.zo·ol?o·gist n.Usage Note: Traditionally, the first syllable of zoology has been pronounced as (z?), 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 (zo?o) is also commonly heard. In 1999, 88 percent of the Panelists found the (z?-) pronunciation acceptable, and 60 percent found the (zo?o-) pronunciation acceptable, with 68 percent using the (z?-) pronunciation and 32 percent using the (zo?o-) pronunciation in their own speech. Thus, while both pronunciations can be considered acceptable, the (z?-) pronunciation may be perceived as more scientific.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.zo?ol?o?gist (zo???l ? d??st) n. a specialist in zoology. [1655?65] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.