The devil is the name given to a supernatural entity, who, in most Western religions, is the central embodiment of evil. This entity is commonly referred to by a variety of other names, including Satan, Asmodai, Beelzebub, Lucifer and/or Mephistopheles. In classic demonology, however, each of these alternate names refers to a specific supernatural entity, and there is significant disagreement as to whether any of these specific entities is actually evil.
In the tradition of the Christian Church, Lucifer was an archangel, who had God's favor as the first angel among equals, but because of his vanity, hubris and weakness of character fell so far from God's grace that he was literally cast out of Heaven when he led other angels in revolt.
As the Devil, Lucifer is a symbol for chaos, and a wild, uncontrollable spirit cursed with all the vices and worst aspects of the human condition. Images of Satan as being red, having horns, cloven hooves and a tail are all efforts by a Church hierarchy to literally and figuratively demonize the image of the fallen Lucifer.
In other languages devil may be derived from the same Proto-Indo-European root word for deva, which roughly translates as "angel". However, a "deva" or "diva" is not a devil.
As a tattoo, a Devil design symbolizes a mischievous, lascivious, and perhaps slightly wicked nature with a predisposition towards all manner of sinful behavior and other vices!