noun
boiled pine pitch and oil glue; traditional archery glue
A traditional adhesive made by boiling pine resin with oil, historically used in Japanese archery for attaching feathers to arrows and other repairs. The term is specialized and mostly encountered in historical or traditional crafts contexts.
昔の弓師は矢羽を付けるのに薬煉を使った。
Old bow makers used kusune to attach arrow feathers.
薬煉は松脂と油を煮詰めて作られる。
Kusune is made by boiling down pine resin and oil.
The reading くすね is of uncertain origin. The kanji 薬煉/薬練 literally mean 'medicine' + 'refine/knead', possibly referring to the preparation process. The ateji spellings 天鼠子 and 天鼠矢 are obscure and their connection to the word is unclear.