Main Entry: ¹ac·id

Pronunciation: \ˈa-səd\

Function: adjective

Etymology: French or Latin; French acide, from Latin acidus, from acēre to be sour — more at acet-

Date: 1626

1 a : sour, sharp, or biting to the taste <an acid flavor> b : sharp, biting, or sour in manner, disposition, or nature <an acid individual> <an acid personality> c : sharply clear, discerning, or pointed <an acid wit> <acid criticism> 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 NaHCO₃> c : containing or involving the use of an acid (as in manufacture) <an acid bath> d : marked by or resulting from an abnormally high concentration of acid <acid indigestion>
3 : relating to or made by a process (as in making steel) in which the furnace is lined with acidic material and an acidic slag is used
4 : rich in silica <acid rocks>

— ac·id·ly adverb

— ac·id·ness noun