blue devil vs blue angel

blue devil and blue angel both are nouns.

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

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

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

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

blue devil (noun)	blue angel (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