Definition are statments made by people to set limits on the terms that they are using. Just because people in one field define a term in a particular way does not mean that it can't mean something completely different in another field.
"By Religion I Mean ..." Some Possible Definitions Of Cults, New Religions, And Related Groups by Irving Hexham
Berger, Peter - "the human enterprise by which a sacred cosmos is established."
Durkheim Emile - "a unified system of beliefs and practices relative to sacred things."
Frazer, James - "a propitiation or conciliation of powers superior to man which are believed to direct or control the course of nature and human life."
Hegel, George - "the knowledge possessed by the finite mind of its nature as absolute mind."
James, William - "the belief that there is an unseen order, and that our supreme good lies in harmoniously adjusting ourselves thereto."
Kant, Immanuel - "the recognition of all our duties as divine commands."
Marx, Karl - "the self-conscious and self-feeling of man who has either not found himself or has already lost himself again... the general theory of the world... its logic in a popular form... its moral sanction, its solemn completion, its universal ground for consolation and justification. It is the fantastic realization of the human essence..."
Schleiermacher, Friedrich - "a feeling for the infinite" and "a feeling of absolute dependence."
Smart, Ninian - "a set of institutionalized rituals identified with a tradition and expressing and/or evoking sacral sentiments directed at a divine or trans-divine focus seen in the context of the human phenomenological environment and at least partially described by myths or by myths and doctrines."
Stark, Rodney - "any socially organized pattern of beliefs and practices concerning ultimate meaning that assumes the existence of the supernatural."
Whitehead, Alfred North - "what the individual does with his own solitariness."
Weber, Max - "to say what it is, is not possible... the essence of religion is not even our concern, as we make it our task to study the conditions and effects of a particular type of social behavior."