a fine charcoal pencil or stick made from the spindle tree
2.
a drawing done with such a pencil
3.
a dull black brittle form of carbon resembling charcoal, found in certain coals
[C19: from French: spindle tree or charcoal made from it, from Vulgar Latin fūsāgō (unattested) a spindle (generally made from the spindle tree), from Latin fūsus]