After training, he rubbed some embrocation on his sore knees to relieve the pain.

embrocation 是名词，由动词 embrocate（用药油涂抹）加上名词后缀 -ion 构成。这个词来自拉丁语，原指"用药液擦洗或涂抹"，现在特指"用于缓解肌肉疼痛的药油或药膏"。