Definition: The word "invertebrate zoology" refers to a branch of zoology that examines invertebrates (such as jellyfish, crabs, worms, etc.) as well as their evolution, classification, biology, behavior, ecology, and interactions with other organisms. Invertebrates are usually found in the oceans or freshwater habitats, such as rivers, lakes, seas, and wetlands. They have no arms, legs, teeth or any organ system, and live primarily on and through their bodies. This field of study helps us understand how living systems change over time and can help us answer questions about life's origins. The term "zoology" usually refers to all areas of biology, including invertebrate zoology. It includes studies of the structure, physiology, behavior, ecology, evolution, and taxonomy of animals and their interactions with one another. So if you need a specific definition or information on this field, please let me know!