Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of life. When you use the word biological, you're talking about life and living things. You'll recognize the root bio-, meaning life, as in biography — the story of someone's life — and biology — the study of living organisms. As a field of science, biology helps us understand the living world and the ways its many species (including humans) function, evolve, and interact. Advances in medicine, agriculture, biotechnology, and many other areas of biology have brought improvements in the quality of life. 1. Of, relating to, caused by, or affecting life or living organisms: biological processes such as growth and digestion. 2. Having to do with biology. 3. Related by genetic lineage: the child's biological parents; his biological sister. 4. Being male or female by having the chromosomes for that sex: a biological female. BIOLOGICAL definition: 1. connected with the natural processes of living things: 2. related by birth: 3. Biological sex…. Learn more. Biologicals are drugs derived from living cells and cultivated in a laboratory. A biological is a drug, such as a vaccine, that is derived from a living organism. The meaning of BIOLOGICAL is of or relating to biology or to life and living processes. How to use biological in a sentence.