Adjective
1. having or concerned with polarities or contrasts; "a Janus-faced view of history"; "a Janus-faced policy"
(similar) bipolar
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
(synonym) ambidextrous, deceitful, double-dealing, duplicitous, two-faced, double-faced, double-tongued
(similar) dishonest, dishonorable
3. having two faces--one looking to the future and one to the past; "Janus the two-faced god"
(synonym) two-faced
(similar) faced