In his PRINCIPLES, Carl Menger defined one's wealth as all of one's  property holdings that consist of economic goods. This is a functional  definition; however, I would submit that there is no way to attain a  "precise" definition of wealth (in any objective sense of the word)  because any individual's personal assessment of his or her wealth would  vary with time and the changing state of their personal knowledge. 
  
Sam Bostaph