sexenary

from The Century Dictionary.

• In arithmetic, having a scale of notation with the radix 6.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Proceeding by sixes; sextuple; -- applied especially to a system of arithmetical computation in which the base is six.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Proceeding by sixes or in a base of six; sextuple.