warpus
Sommerswerd asked me to change this
To me it means some kind of notion of / believe in some kind of "higher" thing/power/force/aspect what have you. A thing obviously shared with being religious.
The me spirituality is all that, but the supernatural portion is optional. You involve it if you think that the supernatural has anything to do with your own consciousness and/or all of reality. But if you don't, you don't. You can still wonder about those deep questions and look inside yourself, meditate, and become one with yourself, and maybe one with the world.
The higher power in my spirituality might very well be my mind - something that's not 100% understood. By meditating you can tap into its powers and use the experience to attempt to understand yourself better. You don't need anything supernatural for spirituality. It's just that most people end up doing that because organized religions tend to suck most of us into them - worldwide the number has got to be higher than 90%. Not many people decide not to join up and do their own spiritual thing, that's why you rarely hear about it.