Noun

1. A kind of evil brownie or imp.

   1999: J.K. Rowling, Harry Potter and the Prisoner of Azkaban

   After boggarts, they studied Red Caps, nasty little goblinlike creatures that lurked where there had been bloodshed...

2. A breed of poultry.

   Red Cap: A rare member of the English class, these are characterized by having a large rose comb. They are one of the few breeds with red earlobes that lay white-shelled eggs. Content: Chicken Breeds and Varieties (A2880), John L. Skinner, University of Wisconsin-Madison http://www.ansi.okstate.edu/poultry/chickens/redcap/