The Collaborative International Dictionary of English v.0.48:

Gavelock \Gav"e*lock\, n. [OE. gaveloc a dart, AS. gafeluc; cf.
   Icel. gaflok, MHG. gabil?t, OF. gavelot, glavelot, F.
   javelot, Ir. gabhla spear, W. gaflach fork, dart, E. glave,
   gaff]
   1. A spear or dart. [R. & Obs.]
      [1913 Webster]

   2. An iron crow or lever. [Scot. & North of Eng.]
      [1913 Webster]