'Janus like' definitions:
- ambidextrous,
- bifacial,
- bifold,
- biform,
- bilateral,
- binary,
- binate,
- biparous,
- bivalent,
- conduplicate,
- disomatous,
- double,
- double-faced,
- dual,
- duple,
- duplex,
- duplicate,
- geminate,
- geminated,
- second,
- secondary,
- twin,
- twinned,
- two-faced,
- two-level,
- two-ply,
- two-sided,
- two-story,
- twofold
