The Collaborative International Dictionary of English v.0.48:

Cockaleekie \Cock`a*leek"ie\, cock-a-leekie \cock-a-leekie\, n.
   [From cock + leek.]
   A favorite soup in Scotland, made from a capon highly
   seasoned, and boiled with leeks and prunes; -- called also
   cocky-leeky.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cock-a-leekie
    n 1: soup made from chicken boiled with leeks [syn:
         cock-a-leekie, cocky-leeky]