piciform bird vs pecker

piciform bird and pecker both are nouns.

Word	Noun	Adjective	Verb	Adverb
piciform bird	Yes	No	No	No
pecker	Yes	No	No	No

As nouns, pecker is a hyponym of piciform bird; that is, pecker is a word with a more specific, narrower meaning than piciform bird:

piciform bird: any of numerous nonpasserine insectivorous climbing birds usually having strong bills for boring wood
pecker: bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects

Other hyponyms of piciform bird include peckerwood, woodpecker, barbet, puffbird, honey guide, jacamar, toucan.

piciform bird (noun)	pecker (noun)
any of numerous nonpasserine insectivorous climbing birds usually having strong bills for boring wood	bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects
	horny projecting mouth of a bird
	obscene terms for penis