tertian noun 3adjective 2forms 1 noun3 •A tertian fever.He died of the slow fever call'd the tertian, / And left his widow to her own aversion. — 1819 •A Jesuit going through tertianship. •A cask of a certain size; its volume used as a measure of capacity (one-third of a tun's). adjective2 •Characterised by paroxysms recurring every other day (that is, every third day by inclusive reckoning). •Pertaining to the mean-tone temperament, in which major thirds are perfectly in tune. formstertians
