ɪˈɹætɪk məːˈkjʊə.ɹɪ.əl mɝˈkjʊ.ɹi.əl ˈplæ.nə.ˌtɛr.i ˈkwɪkˌsɪlvɚ ˈwɑndəɹɪŋ ˈwɒndəɹɪŋ 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 likely to perform unpredictably erratic winds are the bane of a sailor a temperamental motor: sometimes it would start and sometimes it wouldn't that beautiful but temperamental instrument the flute having no fixed course an erratic comet his life followed a wandering course a planetary vagabond