What does "cis" isomer mean in cyclohexane ring?
This, for example, can apply to ortho (1,2 connections) compounds. If carbons 1 and 2 have non-hydrogen substituents, trans implies that one substituent is in the back and one is in the front. If both are in front or both are in back, it is cis. Note that it also extrapolates to meta (1,3) and para (1,4) connections.