an animal being fattened or suitable for fattening
"The farmer selected several young calves as feeders to raise quickly before selling them at market."
a machine that automatically provides a supply of some material
"the feeder discharged feed into a trough for the livestock"
an outdoor device that supplies food for wild birds
"The children filled the feeder with sunflower seeds to attract sparrows to their backyard garden."
One who feeds, or gives food to another.
"The dedicated feeder brought fresh vegetables every morning to ensure the birds stayed healthy."
In plain English: A feeder is something that provides food to animals, plants, or people who need it.
"The cat jumped onto the bird feeder to watch for food."
Usage: A feeder refers specifically to an animal that eats other animals rather than plants; use this term only when describing carnivorous behavior like that of wolves feeding on deer. Do not confuse it with a device used for dispensing food automatically.
Feeder comes from Middle English and is formed by adding the suffix "-er" to the word feed. This construction indicates a person or thing that performs the action of feeding.