vahend materjali eemaldamiseks (söövitamiseks) keemilisel või elektrokeemilisel töötlusel (vt söövitus), 1. a chemical solution used for chemically or electrochemically removing tenacious films from a metal surface to condition the surface for a subsequent treatment, such as painting or electroplating; 2. a chemical solution used to etch a metal to reveal structural details (see: etching)