double-faced (not comparable)

1. Having two functional faces.

   a double-faced hammer

2. deceitful; hypocritical; treacherous
   • 1671, John Milton, “Samson Agonistes, […]”, in Paradise Regain'd. A Poem. In IV Books. To which is Added, Samson Agonistes, London: […] J[ohn] M[acock] for John Starkey […], →OCLC ↗:

     Fame , if not double-faced , is double-mouthed ,
     And with contrary blast proclaims most deed

• two-faced
• Janus-faced