rosin
1. ros.in \'ra:z-*n, 'ro.z-, dial 'ro.-z*m\ n [ME, modif. of MF resine resin] : a translucent amber-colored to almost black brittle friable resin that i s obtained by chemical means from the oleoresin or dead wood of pine trees or from tall oil and used in making varnish, paper size, soap, and soldering flux and on violin bows 2. rosin \'ra:z-nin, 'ro.z-, -*n-in\ vt or ros.in.ing : to rub with rosin (as the bow of a violin)