Source : Webster's Revised Unabridged Dictionary (1913)

Acidic \A*cid"ic\, a. (Min.)
   Containing a high percentage of silica; -- opposed to
   {basic}.

Source : WordNet®

acidic
     adj 1: being or containing an acid; of a solution having an excess
            of hydrogen atoms (having a pH of less than 7) [ant: {alkaline},
             {amphoteric}]
     2: tasting sour like acid [syn: {acidulent}, {acidulous}]