The Collaborative International Dictionary of English v.0.48:

Chebacco \Che*bac"co\, n. [From Chebacco, the former name of
   Essex, a town in Massachusetts where such vessels were
   built.] (Naut.)
   A narrow-sterned boat formerly much used in the Newfoundland
   fisheries; -- called also pinkstern and chebec.
   --Bartlett.
   [1913 Webster]