blue angel vs blue devil

blue angel and blue devil both are nouns.

Word	Noun	Adjective	Verb	Adverb
blue angel	Yes	No	No	No
blue devil	Yes	No	No	No

As nouns, blue angel and blue devil are synonyms defined as:

blue angel and blue devil: the sodium salt of amobarbital that is used as a barbiturate; used as a sedative and a hypnotic

Other synonyms of blue angel include amobarbital sodium, Amytal, blue.

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