The term 'ornithology' is an 11-letter word which refers to the scientific study of birds. It is a branch of zoology that deals with the biology and behavior of birds, as well as their classification and conservation. Ornithologists study the physical characteristics of birds, their anatomy, physiology, genetics, ecology, and evolution. They also study the behavior of birds in the wild, such as their migration patterns, nesting habits, and communication. Ornithology is an important field of study, as it helps us to understand the impact of human activities on bird populations and ecosystems.