The Devil is all about ignorance, obsession, and materialism over spirituality.
In this present position of the reading, it indicates that you may be in the throes of some sort of obsession, addiction or bad habit that is causing you pain. It may be so ingrained that you struggle to recognise it. You may feel trapped, but it will not always be this way.
This card is associated with Earth and Capricorn in a wider sense, and keywords that are associated with The Devil are: