beak vs pecker

beak and pecker both are nouns.

Word	Noun	Adjective	Verb	Adverb
beak	Yes	No	Yes	No
pecker	Yes	No	No	No

As nouns, beak and pecker are synonyms defined as:

Other synonyms of beak include bill, neb, nib.

beak (noun)	pecker (noun)
horny projecting mouth of a bird	bird with strong claws and a stiff tail adapted for climbing and a hard chisel-like bill for boring into wood for insects
beaklike mouth of animals other than birds (e.g., turtles)	horny projecting mouth of a bird
informal terms for the nose	obscene terms for penis
a beaklike, tapering tip on certain plant structures

beak (verb)	pecker (verb)
hit lightly with a picking motion