See Also:

cis- (iou)



cis- prefix. In sense 2 also as attrib. adjective cis.
[Latin, from cis preposition.]
Used in words adopted from Latin and in English words modelled on these with the sense 'on this side of' (opp. TRANS-, ULTRA-), occas. retaining orientation from Rome (as cisalpine etc.), but usu. from the user's or the majority's position (as cisatlantic etc.); also occas. of time (as cis-Elizabethan).
Chemistry. (Usu. italicized.) Designating compounds in which two atoms or groups are situated on the same side of a given plane in the molecule (opp. TRANS-). L19.
cisat'lantic adjective on one's own side of the Atlantic L18.
cis'lunar adjective on this side of the moon, between the earth and the moon L19.
cisoid adjective (Chemistry) designating a compound, group, or structure in which two like atoms or groups lie on the same side of a single bond or line of bonds M20.
cispadane adjective on the south (Roman) side of the River Po L18.
cis'pontine adjective on this side of the bridge or bridges; spec. on the north (orig. the better-known) side of the Thames bridges in London: M19.
cis-trans adjective (Chemistry) designating isomerism characterized by cis and trans isomers M20.