I've been asked to get more specific on my threads, but I refrain from doing so. The following example helps explain why.
At one time, I was very interested in getting a definition of the term number. I've finally decided it wasn't worth the effort. Let's say that the idea of number started with the numerals: 1,2,3,4.... So in starting with the numerals, we can count with them and use them to denote quantity (which occurred first in history, I don't know). Then later on, the concept of zero came into being and that numeral was added to the list. Then came the negative numbers and the fractions and vectors and complex numbers (not exactly in historical order). And other types of numbers were invented or discovered.
The point is that limiting the term number to a specific idea would have slowed up mathematical advancement. What I said here also applies to science, e.g. what is a universe? By being narrowminded may prevent scientific progress from occurring.
PhilX