[Olog-hai]

They’re terms from organic chemistry, misapplied to so-called “gender identity”.

A cis-oriented isomer (“isomer” meaning a molecule with all the same atoms, but in different places depending on the molecule) has certain identifying chemical groups on the same side of the molecule, while a trans-oriented isomer has them on opposite sides. (Illustration below shows the cis and trans isomers of 2-butene.)

[outofsalt]

Those have now been reclassified to front hole butane and back hole butane. Try to keep up.