Dictionary definition · acid
noun
- any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
- street name for lysergic acid diethylamide
adjective
- harsh or corrosive in tone"an acerbic tone piercing otherwise flowery prose"
- being sour to the taste
- having the characteristics of an acid"an acid reaction"
Source: Open English WordNet (CC BY 4.0).