"Cis" is a made-up word that I am mocking (see tagline). I don't know about the non-binary thing. Maybe it's for people that don't understand TCP/IP V4 addressing and subnetting.
Latin was a real language they spoke (and not British accented English) in Rome (Not Latin America)
Cis is Latin "on this side". Cisalpine Gaul "that bit of Gaul this side of the Alps'.
It also identifies isomer structure in chemistry.
It has no other meaning.