Quick definitions from WordNet (blue devil)
▸ noun: a coarse prickly European weed with spikes of blue flowers; naturalized in United States
▸ noun: the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic
▸ noun: a coarse prickly European weed with spikes of blue flowers; naturalized in United States
▸ noun: the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic