As a Noun: 1. The part of a cell in a living thing which controls its physical characteristics, growth, and development. English = gene. 2. The study of heredity and how qualities and characteristics are passed on from one generation to another by means of genes. English = genetics. 3. An abbreviation for `deoxyribonucleic acid'. DNA is found in the chromosomes of the cells of living things. DNA determines the particular structure and functions of every cell and is responsible for characteristics being passed on from parents to their children. English = DNA, deoxyribonucleic acid.