/jay"neuhs fayst'/ , adj.
1. having two faces, one looking forward, one looking backward, as the Roman deity Janus.
2. having two contrasting aspects, as the alternation of mood in a capricious person.
3. two-faced; deceitful.
4. aware of or concerned with polarities; seeing different and contrasting aspects: a Janus-faced view of history.
5. having or containing contrasting characteristics: a Janus-faced policy.
[ 1675-85 ]