TECHNICALLY a Pagan is anyone NOT of the Christian faith. To call a Wiccan a Pagan actually is an insult. Same to call a Druid a Pagan. Pagans were actually more associated with Satanics.
The etymology of "pagan" comes from the Roman "pagani," which mean hill folk or country dwellers. It was a term of derision for the uneducated laborers who worked the land. Until the advent of Christianity as a major monotheistic religion, it was unnecessary to use "polytheistic" since most cultures believed in many gods. Zoroastrianism and Judaism are two exceptions, but even within Zoroastrianism, there was Mithra, a Christlike figure who was the go-between humans and Ahura Mazda.
"Pagan" predates the concept of Satan and has come to mean "polytheistic." Wiccans are pagan and so were the Druids--so are Hindus and many other religions. The only reason I can think of as to why a Wiccan would resent being called pagan is that it is often used as a term of scorn by mainstream Christians. Regardless of any resentment, Wiccans ARE pagans.
I have known many pagans, including Wiccans, and I have never known one to be insulted by the word "pagan."
Jews and Muslims are not pagans; even dictionary.com defines the word as someone not a Christian, Jew, or Muslim; any monotheistic faith would fall into the same category.
However, both "pagan" and "heathen" are sometimes used to refer to a person who has no religious beliefs. Interestingly, the Romans called Jews and Christians "atheists" because they didn't believe in the Roman gods.
