Sentence:  The <WSD>pentacle</WSD>—a pentagram enclosed within a surrounding circle—as found as the centre-piece on a witch's altar is often worn as a silver pendant by witches and other neo-pagans alike repesenting their beliefs in the interconnectedness and interdependence of the powers of nature and spirit. 
Meaning of the word marked with <WSD> tags:  A circumscribed pentagram.