cis-. 2

from The Century Dictionary.

• noun On this side of (a designated period of time): as, “cis-Reformation,” , “cis-Elizabethan,”
• noun In chem., a prefix used, in contrast with trans- or cis-trans-, to designate a compound in which two atoms or groups are supposed to be situated on the same side of some plane of symmetry passing through the compound.