[jyl]

Seem to me the 5th dimension can be any attribute that is not described by position or time.

It can be temperature, color, electric charge, hardness, opacity, odoriferousness, etc.

So you could define a thing by the x-y-z coordinates of the space it occupies, the time (default is present day but could be describing a thing as it existed in 12,000 BC), and that it is mostly black and brown, 98F, overall neutrally charged, mostly soft, fully opaque, very very smelly, etc. Maybe a Neanderthal.