peacock vs peacock butterfly

peacock and peacock butterfly both are nouns.

Word	Noun	Adjective	Verb	Adverb
peacock	Yes	No	No	No
peacock butterfly	Yes	No	No	No

As nouns, peacock and peacock butterfly are synonyms defined as:

peacock and peacock butterfly: European butterfly having reddish-brown wings each marked with a purple eyespot

Other synonyms of peacock include Inachis io.

peacock (noun)	peacock butterfly (noun)
male peafowl; having a crested head and very large fanlike tail marked with iridescent eyes or spots	European butterfly having reddish-brown wings each marked with a purple eyespot
European butterfly having reddish-brown wings each marked with a purple eyespot