double-faced

from WordNet (r) 3.0 (2006)

double-faced
    adj 1: (of fabrics) having faces on both sides; "damask is a
           double-faced fabric"
    2: marked by deliberate deceptiveness especially by pretending
       one set of feelings and acting under the influence of
       another; "she was a deceitful scheming little thing"- Israel
       Zangwill; "a double-dealing double agent"; "a double-faced
       infernal traitor and schemer"- W.M.Thackeray [syn:
       {ambidextrous}, {deceitful}, {double-dealing}, {duplicitous},
       {Janus-faced}, {two-faced}, {double-faced}, {double-tongued}]

from The Collaborative International Dictionary of English v.0.48

Double-faced \Dou"ble-faced`\, a.
   1. Having two faces designed for use; as, a double-faced
      hammer.
      [1913 Webster]

   2. Deceitful; hypocritical; treacherous. --Milton.
      [1913 Webster]