pigmental (p???m?nt?l) adj (Biology) biology of or relating to a pigment or pigments, or the natural colouring of a person or thingCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014