acetic acid

n. ethanoic acid, pungent liquid acid, primary constituent of vinegar

Acetic acid, also known as ethanoic acid, is an organic chemical compound best recognized for giving vinegar its sour taste and pungent smell. Its structural formula is represented as CH3COOH. Pure, water-free acetic acid (glacial acetic acid) is a colourless liquid that attracts water from the environment (hygroscopy), and freezes below 16.7°C (62°F) to a colourless crystalline solid. Acetic acid is corrosive, and its vapour causes irritation to the eyes, a dry and burning nose, sore throat and congestion to the lungs. It is considered a weak acid due to the fact that at standard temperature and pressure the dissociated acid exists in equilibrium with the undissociated form in aqueous solutions, in contrast to strong acids, which are fully dissociated.
See more at Wikipedia.org...

Noun
1. a colorless pungent liquid widely used in manufacturing plastics and pharmaceuticals
(synonym) ethanoic acid
(hypernym) carboxylic acid
(hyponym) acetum
(substance-holonym) diclofenac sodium, Voltaren

noun
acid which turns wine into vinegar

chemical formula CH3COOH, a carboxylic acid, acetic acid is a relatively weak  acid mainly used as a  pH buffer. Acetic acid is commonly sold as a 100% solution and has a density of 1.05Kg/L.