D defs.my
Entry 2 senses Webster, 1913

Acidic

/əsĭdʹĭk/ · A·cid·ic · IPA /əˈsɪ.dɪk/
01 a. Containing a high percentage of silica; -- opposed to basic.
  1. 1.
    Containing a high percentage of silica; -- opposed to basic.(Min.)
  2. 2.
    of or relating to acid; having the character of an acid, as an acidic solution.