Valerie Tarico has written an essay in support of the idea that non-theists should precisely define and adopt the term "spirituality."
This blogger thinks that it is naive to believe one can divorce "spirituality", "sacred" and "soul" from religion simply by redefining them. Terms such as wonder, awe, love, joy, forgiveness, connectedness, moral, evil and goodness are perfectly honest ways of communicating feelings and non-material reality. When using terms such as these, there is no ambiguity regarding the secular and religious. Leave the terms such as spiritual, soul, sacred and spirituality to those who accept concepts without evidence. Language is large enough to adequately describe any real concept in non-religious ways.