ɪˈɹætɪk haɪˈdɹɑːd͡ʒɪɹəm məːˈkjʊə.ɹɪ.əl mɝˈkjʊ.ɹi.əl ˈməː.kjʊ.ɹi ˈmɝkjəɹi ˈkwɪkˌsɪlvɚ ˈkwɪkˌsɪlvɚ liable to sudden unpredictable change erratic behavior fickle weather mercurial twists of temperament a quicksilver character, cool and willful at one moment, utterly fragile the next a heavy silvery toxic univalent and bivalent metallic element; the only metal that is liquid at ordinary temperatures