undecennary

English

Adjective

undecennary (not comparable)

1. (rare) Once every eleven years; undecennial.
   • 1783, Dr. E. Stiles, election sermon

     an undecennary account laid before Parliament

References

• “undecennary”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.