70 () posted 1 year ago by folx 1 year ago by folx +70 / -0 53 comments share 53 comments share save hide report block hide replies
It's a latin prefix meaning "On the near side of" ...
https://www.etymonline.com/word/cis-
A single LiveJournal user saw that "cis" is the opposite of "trans" in chemistry and ran with it.