An appendage is something that is joined to or connected with something larger or more important.
例句
...the growing demand in Wales for recognition that it was not just an appendage to England...有越来越多的威尔士人要求得到认可，即威尔士不只是英格兰的附属Macmillan must have loathed being judged as a mere appendage to domestic politics.麦克米伦肯定极不喜欢只被当成国内政治的附属品。