tricenary

From Latin trīcēnārius, from trīcēnus (“thirty each”) + -ārius (“-ary: forming adjectives and related nouns”).

tricenary (not comparable)

1. (obsolete) Of or related to the number thirty.
2. (obsolete) Lasting thirty days.
   • 1655, T. Stanley, History of Philosophy, Vol. I, Ch. 3:

     After Solon's time, the Civill year was Lunary... though diverse places of Greece,... did not for a long time after part with their tricenary months.

From Medieval Latin trīcēnārium, from Latin trīcēnārius + -ium.

tricenary (plural tricenaries)

1. (Christianity) Synonym of trental, a set of 30 requiem masses.

• “tricenary”, in OED Online ⁠, Oxford: Oxford University Press, launched 2000.