26 from wikipedia
In the medieval period a weapon similar to the halberd was called a bill or billhook. It consisted of a pole with a bill-like blade mounted below a spearhead, with spikes added to the back of the blade to increase the versatility of the weapon against cavalry and armour. The English in particular were known for using massed billmen rather than pikes or halberds in the Renaissance period.
The billhook is an issued tool in some armed forces (see fascine knife). It is used for cutting brushwood for making fascines (brushwood bundles) and gabions—originally for the construction of cannon emplacements, and later for machine gun emplacements. It is also issued to the pioneer corps of most regiments. In the Indian Army, it is given the name 'knife gabion'.
A non-military use as a weapon was a "pruning bill", described as the weapon used in the Pierre Rivière parricide case of 1835.