The Collaborative International Dictionary of English v.0.48:

Killock \Kil"lock\, n. [Cf. Scot. killick "the flue [fluke] of
   an anchor." --Jamieson.]
   A small anchor; also, a kind of anchor formed by a stone
   inclosed by pieces of wood fastened together. [Written also
   killick.]
   [1913 Webster]