Source : Webster's Revised Unabridged Dictionary (1913)

Billhook \Bill"hook`\, n. [Bill + hook.]
   A thick, heavy knife with a hooked point, used in pruning
   hedges, etc. When it has a short handle, it is sometimes
   called a {hand bill}; when the handle is long, a {hedge bill}
   or {scimiter}.

Source : WordNet®

billhook
     n : a long-handled saw with a curved blade; "he used a bill to
         prune branches off of the tree" [syn: {bill}]