Billet (wood) was a specific and standardised form of wood fuel of significant importance in the traditional pre-fossil fuel economy. The term could also be applied to a cudgel.
Billets were especially designed for burning on open hearth fires, often in conjunction with spits.
The 16th C standardised a billet as three foot four inches in length, and ten inches around.
A century later, Anthony A Wood recorded a load of billet wood as costing 12s 6d; while extravagance consisted of "burning in one yeare threescore pounds worth of the choicest billet".