# noun. - a chemical substance that neutralizes alkalis, dissolves some metals, and turns litmus red; typically, a corrosive or sour-tasting liquid of this kind. * traces of acid - a molecule or other entity that can donate a proton or accept an electron pair in reactions. * None - the drug LSD. * she didn't have a clue the candy had acid in it
# adjective. - containing acid or having the properties of an acid; having a pH of less than 7. * poor, acid soils - sharp-tasting or sour. * acid fruit - (of rock, especially lava) containing a relatively high proportion of silica. * the magma may start off fairly basic and end up at the close of the eruption much more acid