A more thorough explanation:

Definition: Nova custuma (noh-və kəs-təm-ə), n. [Law Latin “new custom”] refers to a tax or an imposition in historical context.

Example: In medieval England, the king imposed a nova custuma on wool exports, which was a new tax on top of the existing antiqua custuma (old custom) tax.

Explanation: The example illustrates how nova custuma was used as a means of generating revenue by imposing a new tax on a particular commodity. The term was commonly used in medieval times to refer to new taxes or impositions that were introduced by the ruling authority.