downy woodpecker vs peckerwood

downy woodpecker and peckerwood both are nouns.

Word	Noun	Adjective	Verb	Adverb
downy woodpecker	Yes	No	No	No
peckerwood	Yes	No	No	No

As nouns, peckerwood is a hypernym of downy woodpecker; that is, peckerwood is a word with a broader meaning than downy woodpecker:

downy woodpecker: small North American woodpecker with black and white plumage and a small bill
peckerwood: bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects

Other hypernyms of downy woodpecker include pecker, woodpecker.

downy woodpecker (noun)	peckerwood (noun)
small North American woodpecker with black and white plumage and a small bill	bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects