tertian

Recurring every other day or, when considered inclusively, every third day.

A tertian fever, such as vivax malaria.

Occurring every second day.

A fever or other disease whose paroxysms return after a period of two days, or on the third day, reckoning both days of consecutive occurrence; an intermittent whose paroxysms occur after intervals of about forty-eight hours.

In organ-building, a stop consisting of a tierce and a larigot combined.