The Collaborative International Dictionary of English v.0.48:
Hayfork \Hay"fork`\ (h[=a]"f[^o]rk`), n. A fork for pitching and tedding hay. [1913 Webster] Horse hayfork, a contrivance for unloading hay from the cart and depositing it in the loft, or on a mow, by horse power. [1913 Webster]