I believe this hand-forged and rasped iron tool was made for a farrier's use--with the rasped areas on either side used for filing a horse's hooves; the extended, arched blade, with one quite sharp edge, used for shoeing; and the hooked short end as a pick. I'm no expert on hoof care, but I do believe that's what this is, and a very custom, antique example. If without horses around to care for, one could use it, say, as a letter opener, with those rasped sections making quite a nice handle to wrap a hand around, but I'd be content just to look at it, quite a beautiful and beautifully made object. 

9 1/4" l measured on the square, 1 1/16" widest. Beautiful used and aged antique condition.