Spirituality is such a heavy word. It comes with a baggage filled with contradictions. It is used differently by different people, but the people who use the word almost always assume that everyone uses the word the same way and they aren’t usually sensitive to this fact. For example, most Christians I talk to almost always equate spirituality to a reverence of a personified God. But there is a large collective of people who don’t define God as a person and therefore could not find such a definition of spirituality useful.
My initial response to this problem is to use a different word altogether. jon kabat-zinn suggested that the word “spiritual” should be substituted by the word “conscious” to signify “focused attention” or mindfulness.
There is another way, of course, and that is to borrow the word BUT always be clear on how one defines it. I find it useful to equate spirituality with reverence towards something.
For example, feel reverence to things we hold “sacred.” We don’t revere it and consider it worthy of our dedication unless we recognize its importance and significant to our life. I don’t go to nature and write poems about it unless I feel first that I value it enough to hold it sacred. So spirituality I think is closest to what I feel when I feel in awe to the intelligibility and yet mystery of reality.