quartan


quartan
quar•tan
[[t]ˈkwɔr tn[/t]] adj.
1) pat recurring every fourth day, both days of consecutive occurrence being counted:
quartan fevers[/ex]
2) pat a quartan fever, ague, etc
Etymology: 1250–1300; ME quartaine < OF < L (febris) quārtāna quartan (fever), fr. quārt(us) fourth+-ānus -an I

From formal English to slang. 2014.