Real Dictionary

acid
a cleansing agent, esp a surface-active chemical such as an alkyl sulphonate, widely used in industry, laundering, shampoos, etc [...]
an enzyme that catalyses a process of synthesis [...]
any of a group of enzymes that catalyse the hydrolysis of organic phosphates [...]
any of a large group of nitrogenous compounds of high molecular weight that are essential constituents of all living organisms. They consist of one or more chains of amino acids linked by peptide bonds and are folded into a specific three-dimensional shap
any substance that dissociates in water to yield a sour corrosive solution containing hydrogen ions, having a pH of less than 7, and turning litmus red [...]
the act or process of oxidizing [...]
the application of medicines, surgery, psychotherapy, etc, to a patient or to a disease or symptom [...]
the formation of complex compounds from simple substances by living organisms [...]
the sum total of the chemical processes that occur in living organisms, resulting in growth, production of energy, elimination of waste material, etc [...]
variable noun: An acid is a chemical substance, usually a liquid, which contains hydrogen and can react with other substances to form salts. Some acids burn or dissolve other substances that they come into contact with.