tertian

alternative historical tercian

1. not comparablemedicineCharacterised by paroxysms recurring every other day (that is, every third day by inclusive reckoning).
2. not comparableentertainmentPertaining to the mean-tone temperament, in which major thirds are perfectly in tune.

plural tertians · alternative historical tercian

1. A tertian fever.

   He died of the slow fever call'd the tertian, / And left his widow to her own aversion.

   1819, Lord Byron, Don Juan, Canto 1

   1 more example

   And although we feele it not, it is not to bee doubted, if a continuall ague may in the end suppresse our mind, a tertian will also (according to her measure and proportion) breed some alteration in it.

   1603, Michel de Montaigne, chapter 12, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […], →OCLC

2. A cask of a certain size; its volume used as a measure of capacity (one-third of a tun's).

   Synonyms: puncheon

3. A Jesuit going through tertianship.