Pronunciation: (roz'in), [key]
—n. Also called colophony.
1. Chem.the yellowish to amber, translucent, hard, brittle, fragmented resin left after distilling the oil of turpentine from the crude oleoresin of the pine: used chiefly in making varnishes, varnish and paint driers, printing inks, and for rubbing on the bows of such string instruments as the violin.
to cover or rub with rosin.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.