Lampblack is a black powdery substance made from the SOOT produced by burning oil, tar, or other materials. It is composed of carbon particles and is used in printing, painting, and dyeing. The term 'lampblack' is derived from the fact that it was traditionally produced by collecting SOOT from oil lamps. The crossword solution for the term 'lampblack' is 'SOOT', which is a fine black powdery substance consisting of carbon particles that is produced by the incomplete combustion of organic materials.