rosin

the hard, brittle resin, light-yellow to almost black in color, remaining after oil of turpentine has been distilled from crude turpentine or obtained from chemically treated pine stumps: it is used in making varnish, inks, soaps, insulation, etc., and is rubbed on violin bows to prevent slipping on the strings, or on the hands to prevent slipping on gymnastic equipment, etc.

to rub with rosin