The Collaborative International Dictionary of English v.0.48:

Foreganger \Fore"gang`er\, n. [Prop., a goer before cf. G.
   voreg[aum]nger. See Fore, and Gang.] (Naut.)
   A short rope grafted on a harpoon, to which a longer line may
   be attached. --Totten.
   [1913 Webster]