tertian

Originally Middle English as part of the collocation fever cum terciane, after Latin febris cum tertiana, from tertius (“third”).

tertian (not comparable)

1. Of a fever, characterised by paroxysms every third day.
2. (music) Pertaining to the mean-tone temperament, in which major thirds are perfectly in tune.

tertian (plural tertians)

1. A tertian fever.
   • 1603, John Florio, transl.; Michel de Montaigne, chapter 12, in The Essayes, […], book II, printed at London: By Val[entine] Simmes for Edward Blount […], OCLC 946730821:

     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.

   • 1819, Lord Byron, Don Juan, Canto 1:

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

2. The puncheon, an old wine cask, three of which made a tun.

• intreat, iterant, natrite, nattier, nitrate, tainter, tartine