WordWeb Online

1. Pluck or pull at with the fingers
   - pluck at, pull at
    
2. Eat like a bird
   "The anorexic girl just picks at her food";
   - peck at, peck
    
3. Express a negative opinion of
   "She picked at her student's efforts";
   - disparage, belittle

Derived forms: picked at, picking at, picks at

Type of: criticise [Brit], criticize, damn, eat, knock, pick apart, pull