Too crude to be a Machete ?

[Jim McDougall]

Many scythes, and 'clearing' or cropping implements had hafts, thus were mounted on these or perhaps even longer, in the manner of pole arms.
Recalling the idiom, 'swords into plough shares' which reflects the cases of weapon into tool, or clearly vice versa, as glaives, bill hooks and the like.

Whatever the case with this item, it is fascinating for its rustic character and clearly obvious age, its 'mystery' not withstanding.

The handle is perhaps not viable for most modern hands, if indeed this was the intent, but overall the hands of individuals centuries ago much as their physical size and structure was generally smaller. However, the 'socket' idea seems quite plausible.