The name 'Arian' may simply mean or refer to someone who is born under the sign of Aries. It may also refer to something that is of or pertaining to Arianism, or someone who is a believer in Arianism.
Arianism is the name of a Christian heresy created by Arius in the fourth century. It was one of the most extensive and discordant heresies ever seen in the history of Christianity. Arius propounded his teachings as a priest in the city of Alexandria. According to him, God made before everything else, a Son who was the primary being, but who was not an equal of the Father. As per Arius, Jesus was a mystic being who was not really human and not quite celestial.
Due to such teachings, Arius faced condemnation and was dispossessed of his office and title. He escaped to Palestine and his doctrine was spread amongst the mass by way of well-liked discourses and songs. He also reached the influential section of the society with the help of powerful leaders like Eusebius of Nicomedia.