quar·tan (kwôrt'n) adj. Occurring every fourth day, counting inclusively, or every 72 hours. Used of a fever. n. A malarial fever recurring every 72 hours.
[Middle English quartaine, from Old French, from Latin quārtāna, from quārtānus, of the fourth, from quārtus, fourth; see kwetwer- in Indo-European roots.]
Main Entry: 1quar·tan Pronunciation: 'kwort-&n Function: adjective : occurring every fourth day reckoning inclusively;specifically: recurring at approximately 72-hour intervals <quartan chills and fever> —compare TERTIAN
Main Entry: 2quartan Function: noun : an intermittent fever that recurs at approximately 72-hour intervals; especially:MALARIAE MALARIA