A Fauchard is a pole with a long and curved blade, the cutting edge being on the concave side.
It greatly resembles a scythe or sickle.
It was soon realized that the design made the weapon rather useless and was then shortly after changed to the Fauchard-fork. The fork being the defining change, rather than one blade, two forked from each other.
Again, I couldn't find very much information about the weapon or even pictures (aside from the modified version) but it is a very interesting weapon and I will definitely be looking into it again in hopes of finding more.
*Disclaimer: I have done extensive research on each of these weapons. I am aware that there are many different versions of each of these weapons. I am not trying to spread false information. If you know and can prove any information wrong, please let me know and I will fix my errors. I have at least three references for all research on the weapons I will discuss through the challenge.