'pick at' definitions:

Definition of 'pick at'

(from WordNet)
verb
Pluck or pull at with the fingers; "She picked nervously at the buttons of her blouse" [syn: pick at, pluck at, pull at]
verb
Eat like a bird; "The anorexic girl just picks at her food" [syn: pick at, peck at, peck]
verb
Express a negative opinion of; "She disparaged her student's efforts" [syn: disparage, belittle, pick at] [ant: blandish, flatter]