It is amazing how many things never change after thousands of years. Also, documenting words and expressions in the Egyptian Colloquial Arabic language, which is not true Arabic. Most of these words and expressions are from the Pharaonic era. This is a major study, which will go on forever. The fourth meaning is the combination of all three meanings, to come up with the fourth meaning.
Water is the sum, the composite principle of fire, earth, and air.
The present academia mentality, is to stay in their comfort zone, following half-assed linear meanings of the Medu. We have no egos or tenure to protect. So it was built and inscribed by the pictorial hieroglyphs, to attract such divine power for the benefit of the people of the land. So we are talking about metaphysical aspects of the universe. In order to understand such aspects, we need to understand the metaphysical in the universe, as well as within ourselves as human beings.