The Collaborative International Dictionary of English v.0.48:

Ambidexter \Am"bi*dex"ter\, a. [LL., fr. L. ambo both + dexter
   right, dextra (sc. manus) the right hand.]
   Using both hands with equal ease. --Smollett.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ambidexter \Am`bi*dex"ter\, n.
   1. A person who uses both hands with equal facility.
      [1913 Webster]

   2. Hence: A double-dealer; one equally ready to act on either
      side in party disputes.
      [1913 Webster]

            The rest are hypocrites, ambidexters, so many
            turning pictures -- a lion on one side, a lamb on
            the other.                            --Burton.
      [1913 Webster]

   3. (Law) A juror who takes money from both parties for giving
      his verdict. --Cowell.
      [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

AMBIDEXTER. It is intended by this Latin word, to designate one who plays on
both sides; in a legal sense it is taken for a juror or embraceor who takes
money from the parties for giving his verdict. This is seldom or never done
in the United States.