silver coin from the early days of the Republic of China (1912-1949) bearing the head of Yuan Shikai 袁世凱|袁世凯[Yuan2 Shi4 kai3]
Definitions (Wiktionary)
noun
silver dollar with the head of Yuan Shikai (as used in the early years of the Republic of China) (syn.) 袁大頭, 老人頭, 大得腦兒, 明山大洋, 大腦殼, 大頭, 袁頭, 袁大腦殼, 大袁頭, 大腦蓋