A more thorough explanation:

PROFICUA

Proficua (prə-fik-yoo-ə). [Law Latin] Historical term used to refer to the profits or income generated by an estate in land.

• The proficua of the estate was used to pay for the upkeep of the property and support the landowner's family.
• During the Middle Ages, lords and nobles relied on the proficua of their estates to maintain their status and power.

The examples illustrate how proficua was used to describe the income or profits generated by an estate in land. In the first example, the proficua was used to cover the expenses of the property and support the landowner's family. In the second example, the proficua was a source of power and influence for lords and nobles during the Middle Ages.