quicksilver /ˈkwɪkˌsɪlvɚ/noun 2verb 2adjective 1forms 3 noun2 •(literary) The metal mercury. •(literary) An amalgam of mercury and tin applied to the backs of mirrors; quicksilvering. verb2 •To overlay with quicksilver. •To treat with quicksilver. adjective1 •(literary) Unpredictable, erratic, or fickle; mercurial.Summer is not the most auspicious season for theater in New York. Aside from a few certifiable Broadway hits, it is, in fact, a rather quicksilver commodity. — 1978 formsquicksilvered · quicksilvering · quicksilvers