Source : WordNet®

blue devil
     n 1: a coarse prickly European weed with spikes of blue flowers;
          naturalized in United States [syn: {blueweed}, {blue
          thistle}, {viper's bugloss}, {Echium vulgare}]
     2: the sodium salt of amobarbital that is used as a
        barbiturate; used as a sedative and a hypnotic [syn: {amobarbital
        sodium}, {blue}, {blue angel}, {Amytal}]