Duo*dec"i*mal*ly

from The Collaborative International Dictionary of English v.0.48

Duodecimal \Du`o*dec"i*mal\, a. [L. duodecim twelve. See
   {Dozen}.]
   Proceeding in computation by twelves; expressed in the scale
   of twelves. -- {Du`o*dec"i*mal*ly}, adv.
   [1913 Webster]