Answer: quartan

AnswerCrossword Clue
QUARTANOccurring every fourth day.
QUARTANRecurring every fourth day
quartana recurrent malarial fever
quartanquartan fever or ague
quartanquartan malaria
quartan(of a fever, ague, etc.) characterized by paroxysms that recur every fourth day, both days of consecutive occurrence being counted