Oxygen-deprived is a term used to describe an environment or organism that is lacking in oxygen. Anoxic is a 6 letter word that is synonymous with oxygen-deprived, and is used to describe a state of oxygen deficiency. Oxygen-deprived environments can be caused by a variety of factors, such as a lack of oxygen in the atmosphere, or a decrease in the amount of oxygen available in the water. Oxygen-deprived organisms can suffer from a variety of health problems, including difficulty breathing, fatigue, and even death.