1. Abnormally high acidity of the blood and body tissues caused by a deficiency of bicarbonates or an excess of acids other than carbonic acid. It can result from any of various acute or chronic disorders or from the ingestion of certain drugs and toxins. Also called metabolic acidosis.

2. Abnormally high acidity of the blood and body tissues caused by an excess of carbon dioxide due to hypoventilation. Also called respiratory acidosis.