Quar"tan (?), a. [F. quartain, in fievre quartaine, L. quartanus, fr. quartus the fourth. See Quart.]
Of or pertaining to the fourth; occurring every fourth day, reckoning inclusively; as, a quartan ague, or fever.
© Webster 1913.
Quar"tan, n.
1. Med.
An intermittent fever which returns every fourth day, reckoning inclusively, that is, one in which the interval between paroxysms is two days.
2.
A measure, the fourth part of some other measure.
© Webster 1913.