pick at vs peck

pick at is not a noun while peck is a noun.

Word	Noun	Adjective	Verb	Adverb
pick at	No	No	Yes	No
peck	Yes	No	Yes	No

As verbs, pick at and peck are synonyms defined as:

Other synonyms of pick at include peck at.

pick at (noun)	peck (noun)
	a light kiss
	bite by a bird
	(often followed by `of') a large number or amount or extent
	a United States dry measure equal to 8 quarts or 537.605 cubic inches
	a British imperial capacity measure (liquid or dry) equal to 2 gallons

pick at (verb)	peck (verb)
express a negative opinion of	bother persistently with trivial complaints
eat like a bird	eat by pecking at, like a bird
pluck or pull at with the fingers	eat like a bird
	kiss lightly
	hit lightly with a picking motion