Definition - What does Anaerobic mean?
Anaerobic refers to a type of environment that consists of a partial or complete lack of oxygen. It may also refer to a type of corrosion that occurs in the presence of anoxic water.
Corrosionpedia explains Anaerobic
Anaerobic corrosion is most readily observed when a metal is placed or used in an environment with a high concentration of bacteria. These bacteria can survive in areas without oxygen and force metal degradation and/or corrosion via the microorganism's activity. Such a mechanism is primarily observed in the presence of anoxic water.
A major type of anaerobic corrosion is hydrogen corrosion, which involves a redox reaction that reduces hydrogen ions to form molecular hydrogen.