undecennis

undecennis [CL undecim+annus+-is], undennis [cf. LL duodennis], a eleven years old. b that lasts for eleven years. c (in gl.). a puella virgoque undennis Gerv. Tilb. III 103.  b toto tempore sue undennis gubernacionis Reg. Whet. I 108.  c decennis ‥ componitur etiam ~is Osb. Glouc. Deriv. 14.