From Middle English feedere, federe, fedare, equivalent to feed + -er.

• (America) IPA: /ˈfidɚ/

feeder (plural feeders)

1. One who feeds, or gives food to another.
   1. The participant in feederism who feeds the other (the feedee).
      • 2010, Niall Richardson, Transgressive Bodies:

        Often similes such as 'soft as velvet' or 'fluffy like a cloud' will be employed and the feeder will describe how he feels he can be lost in the enveloping folds of soft flesh.

2. One who feeds, or takes in food.
   • c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act II, scene v]:

     The patch is kind enough, but a huge feeder,
     Snail-slow in profit, and he sleeps by day
     More than the wild-cat; […]

3. One who, or that which, feed#Verb material into something (especially a machine).

   Coordinate terms: feed, feedbin, hopper

   Hyponyms: barfeed, barfeeder

   • 2007, Thomas E. Lightburn, The Shield and the Shark, page 173:

     When the claxon sounded they immediately stopped what they were doing and uncovered the Oerlikon. Paddy, who was ammunition feeder, stood by while Jock trained the 20mm gun around.

4. That which is used to feed.

   a bird feeder

5. A tributary stream, especially of a canal.
6. A branch line of a railway.
7. A transmission line that feeds the electricity for an electricity substation, or for a transmitter.
8. (education) Short for feeder school.
9. (shipbuilding, navigation) A feeder ship.
10. (US, legal) A judge whose law clerks are often selected to become clerks for the Supreme Court.
11. (baseball, slang, archaic, 1800s) The pitcher.
12. (video games, derogatory) A player whose character is killed by the opposing player or team more than once, deliberately or through lack of skills and experience, thus helping the opposing side.
13. (obsolete) One who abets another.
    • c. 1598–1600 (date written), William Shakespeare, “As You Like It”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC ↗, [Act II, scene iv], lines 815–818:

      Go with me; if you like upon report
      The soil, the profit, and this kind of life,
      I will your very faithful feeder be,
      And buy it with your gold right suddenly.

14. (obsolete) A parasite.