carbonear

A historical/maritime term meaning to take on coal as fuel, especially of a steamship stopping at a port to refuel (carbonear en un puerto), or, in an older agricultural sense, to make or deal in charcoal.

• El buque carboneó en Cádiz antes de cruzar el Atlántico. — The ship coaled at Cádiz before crossing the Atlantic.
• Los mineros carboneaban en los montes cercanos. — The charcoal-burners worked in the nearby hills.
• El vapor tuvo que carbonear dos veces durante el viaje. — The steamship had to coal twice during the voyage.

This is dated, era-specific vocabulary tied to the age of coal-fired ships — don't confuse it with the everyday carbonizar (to char/burn to a crisp).

Often confused with carbonizar.