Pentagram
The word pentacle originally meant 'any symbol that protects against evil spirits'. There are many of such symbols, only a few of which include a pentagram. During the modern age of Wicca, the word 'pentacle' acquired a second definition, due to sounding similar to the word 'pentagram', and the fact that wiccan pentacles use a pentagram. That second definition of 'pentacle' is 'a circumscribed pentagram', which means 'a pentagram drawn inside a circle so that the points of the pentagram touch the circle'.