pyc·no·sis noun orpyk·no·sis\pikˈnōsə̇s\ (-es) Etymology: New Latin, from Greek pyknōsis condensation, from pyknoun to condense (from pyknos dense, thick) + -ōsis -osis — more at pycn- : a degenerative condition of a cell nucleus marked by clumping of the chromosomes, hyperchromatism, and shrinking of the nucleus