heelball /ˈhiːlˌbɔːl/

• 1. 

  N a black waxy substance used by shoemakers to blacken the edges of heels and soles 蜡墨; 擦鞋跟或鞋底用

• 2. 

  N a similar substance used to take rubbings, esp brass rubbings 尤指黄铜拓印使用的类似涂材