rosin
noun [ U ] uk/ˈrɒz.ɪn/ us/ˈrɑː.zən/
松香（一种变硬的黄色树脂，由某些树木和植物生成，特别用于弦乐器的弓丝上，可阻止弓丝在弦上滑动）
yellow resin (= sticky substance produced by certain trees and plants) that has become hard, used especially on the hairs of bows of stringed musical instruments to prevent the hairs from sliding over the strings
Compare: resin