acid means: Acidic substance that has a sharp or sour taste. Acidic foods tend to be mildly acidic. Citrus juice, vinegar and wine are all considered acidic foods. The pH scale measures acidity. Acids have a pH less than 7. (in Cooking Dictionary)

What else does acid mean?

A class of chemicals whose aqueous solution is characterized by a bitter taste and the ability of turning blue litmus into red. They also have the ability react with certain metals and bases to make salts. (in Merlin Dictionary)

Hydrogen ions are produced when substances are dissolved in water. (in Merlin Dictionary)

An element that acts as a proton donor. (in Merlin Dictionary)

An element that accepts two electrons in order to create a covalent bonds. (in Merlin Dictionary)

Sourness is a substance with a bitter taste. (in Merlin Dictionary)

A person who is sarcastic or bitter. (in Merlin Dictionary)

A term that refers to or contains acid. (in Merlin Dictionary)

High acidity (in Merlin Dictionary)

A characteristic of acid. (in Merlin Dictionary)

A pH lower than 7. (in Merlin Dictionary)

A high level of hydrogen ions. (in Merlin Dictionary)