novennium

From Late Latin novennium, from novennis (“9-year”) + -ium (“forming abstract nouns”).

novennium (plural novennia)

1. (rare) A nine-year period.

   Coordinate terms: annum, biennium, triennium, quadrennium, quinquennium, sexennium, septennium, octennium, decennium, vicennium, tricennium, centennium, quincentennium, millennium, decamillennium, centimillennium, millionennium

   • 1871, Henry Scale English, Crowland and Burgh, volume 3, page 148:

     What he says of the novennium is an attempt at duplicity; he would have escaped with that if he could; he did not love to lie: What he says is that Ernulfus was a bishop a little over nine years […]

• See ennead

• (adj.): novennial, enneaeteric, enneatic

• “novennial, adj.”, in OED Online ⁠, Oxford, Oxfordshire: Oxford University Press, 2022.

From novennis (“9-year”) +‎ -ium (“forming abstract nouns”).

novennium n

1. (Late Latin) A nine-year period.

• English: novennium