1) Having two faces or aspects 2) Hypocritical 3) Practicing duplicity 
• (a.) Having two faces designed for use; as, a double-faced hammer. • (a.) Deceitful; hypocritical; treacherous.
Dou'ble-faced` adjective 1. Having two faces designed for use; as, a double-faced hammer. 2. Deceitful; hypocritical; treacherous. Milton. 
[adj] - (of fabrics) having faces on both sides
adjective (of fabrics) having faces on both sides; `damask is a double-faced fabric`
practicing duplicity; hypocritical. · having two faces or aspects. · having two usable sides, esp. two sides designed to be used in the same manner: double-faced adhesive tape.