ciss /sɪs/ verb1 •To retract (from a uniform film applied to a damp, oily or nonabsorbent surface) and clump up into small droplets, or form craters.Varnish is very apt to ciss on old work, if the second coat is not applied as soon as ever the first coat is hard enough to bear varnishing. — 1873 formscissed · cissing · cisses