- Undecennary
- Undecennary Un`de*cen"na*ry, a. [L. undecim eleven (unus one +
decem ten) + -ennary as in decennary. Cf. {Undecennial}.]
Occurring once in every period of eleven years; undecennial.
[1913 Webster]
An undecennary account laid before Parliament. --E. Stiles. [1913 Webster]
The Collaborative International Dictionary of English. 2000.