If one is creating a large number of data elements, all the definitions should be consistent with related concepts.
e.g.: Standards such as the ISO/IEC 11179 Metadata Registry specification give guidelines for creating precise data element definitions.
The process of finding a good meaning of a word is called Word-sense disambiguation Here is the definition of "person" data element as defined in the www.w3c.org Friend of a Friend specification *: Although most people do have an intuitive understanding of what a person is, the definition has much room for improvement.
Here is a more precise but shorter definition of a person: Note that it uses the word individual to state that this is an instance of a class of things called human being.
For example, if your "Person" data element tracked characters in a science fiction series that included aliens you may need a more general term other than human being.