Acidic a. : Containing a high percentage of silica; -- opposed to basic.

Example:
What caused the Acidic state of my aquarium water?

Taxonomy
acids, proton, aq, bond, reactions, H2O, H3O, HCl, hydrogen, molecule, electrons, atom, conjugate base, Lewis acids, oxygen, Ka, electronegative, Ka1.

Defination from the web:
acidic. ... Carboxylic acids are organic acids that contain an acidic hydroxyl group and a carbonyl (C=O bond) ...