Pentagram

A pentagram (sometimes known as a pentalpha or pentangle or, more formally, as a star pentagon) is the shape of a five-pointed star drawn with five straight strokes. The word pentagram comes from the Greek word πεντάγραμμον (pentagrammon), a noun form of πεντάγραμμος (pentagrammos) or πεντέγραμμος (pentegrammos), a word meaning roughly "five-lined" or "five lines", from πέντε (pente), "five" + γραμμή (grammē), "line".
Pentagrams were used symbolically in ancient Greece and Babylonia, and are used today as a symbol of faith by many Wiccans, akin to the use of the cross by Christians and the Star of David by Jews. The pentagram has magical associations, and many people who practice Neopagan faiths wear jewelry incorporating the symbol. Christians once more commonly used the pentagram to represent the five wounds of Jesus. The pentagram has associations with Freemasonry[6] and is also utilized by other belief systems.
The word "pentacle" is sometimes used synonymously with "pentagram", and this usage is borne out by the Oxford English Dictionary, although that work specifies that a circumscription makes the shape more particularly a pentacle. Wiccans and Neo-pagans often make use of this more specific definition for a pentagram enclosed in a circle.

The first known uses of the pentagram are found in Mesopotamian writings dating to about 3000 BC. The Sumerian pentagrams served as pictograms for the word "UB" meaning "corner, angle, nook; a small room, cavity, hole; pitfall," suggesting something very similar to the pentemychos (see below on the Pythagorean use for what pentemychos means). In René Labat's index system of Sumerian hieroglyphs/pictograms it is shown with two points up. In the Babylonian context, the edges of the pentagram were probably orientations: forward, backward, left, right, and "above". These directions also had an astrological meaning, representing the five planets Jupiter, Mercury, Mars and Saturn, and Venus as the "Queen of Heaven" (Ishtar) above.

The Pythagoreans called the pentagram ὑγιεία Hugieia ("health"; also the Greek goddess of health, Hygieia), and saw in the pentagram a mathematical perfection (see Geometry section below).
The ancient Pythagorean pentagram, with two legs up, represented the Pentemychos (πεντέμυχος "of five sanctuaries"), a cosmogony written by Pythagoras' teacher and friend Pherecydes of Syros. It was the "island" or "cave"[13] where the first pre-cosmic-offspring had to be put in order for the cosmos to appear: "the divine products of Chronos' seed [σπέρμα spérma], when disposed in five recesses, were called Πεντέμυχος (Pentemuxos)".