Undecennary
Undecennary , adjective
[Latin undecim eleven (unus one + decem ten) + -ennary as in decennary. Compare Undecennial.]
Occurring once in every period of eleven years; undecennial.
An undecennary account laid before Parliament.
Undecennary , adjective
[Latin undecim eleven (unus one + decem ten) + -ennary as in decennary. Compare Undecennial.]