Acid

Main Entry: ac·id Pronunciation: 'a-s&d Function: adjective Etymology: French or Latin; French acide, from Latin acidus, from acEre to be sour -- more at ACET- 1 a : sour, sharp, or biting to the taste b : sharp, biting, or sour in manner, disposition, or nature <an acid individual> c : sharply clear, discerning, or pointed <an acid wit> d : piercingly intense and often jarring <acid yellow> 2 a : of, relating to, or being an acid; also : having the reactions or characteristics of an acid <acid soil> <an acid solution> b of salts and esters : derived by partial exchange of replaceable hydrogen <acid sodium carbonate Na₂CO₃ c : containing or involving the use of an acid (as in manufacture) d : marked by or resulting from an abnormally high concentration of acid <acid indigestion>.