Definition of "Feeder" :

noun: an animal being fattened or suitable for fattening

noun: an animal that feeds on a particular source of food

"A bark feeder."

noun: an outdoor device that supplies food for wild birds

noun: a machine that automatically provides a supply of some material

"The feeder discharged feed into a trough for the livestock."

noun: a branch that flows into the main stream

noun: someone who consumes food for nourishment