acid
Cross references:
1. sour
1. ac.id \'as-*d\ aj [F or L; F acide, fr. L acidus, fr. ace-re to be sour
-]more at ACETIC 1a: sour, sharp, or biting to the taste 1b: sharp,
biting, or sour in manner, disposition, or nature 1c: sharply clear,
discerning, or pointed 2a: of, relating to, or being an acid; also :
having the reactions or characteristics of an acid 2b: marked by excessive
or abnormal concentration of acid 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 - ac.id.ly av
2. acid n : a sour substance; specif : any of various typically
water-solubl e and sour compounds capable of reacting with a base to form a
salt that are hydrogen-containing molecules or ions able to give up a
proton to a base or substances able to accept an unshared pair of electrons
from a base