Pharaoh

The word originally meant 'house with columns': which is to say, a great house:

The term pharaoh ultimately was derived from a compound word represented as pr-`3, written with the two biliteral hieroglyphs pr "house" and `3 "column". It was used only in larger phrases such as smr pr-`3 'Courtier of the High House', with specific reference to the buildings of the court or palace itself ... From the nineteenth dynasty onward pr-`3 on its own was used as regularly as 'His Majesty'. The term therefore evolved from a word specifically referring to a building to a respectful designation for the ruler, particularly by the twenty-second dynasty and twenty-third dynasty ... By this time, the Late Egyptian word is reconstructed to have been pronounced *par-ʕoʔ whence comes Ancient Greek φαραώ pharaō and then Late Latin pharaō. From the latter, English obtained the word "Pharaoh".

But was this usage originally metonymic: for the powerful families in Egypt were the ones who lived in swanky houses with columns? Or was it metaphoric: for a mighty ruler is a house in which his people can find shelter, protection and comfort?