Why were they called Pyramids

Erodoto visited Egypt between 460 and 455 BC.
In his book “Stories” the word pyramid is used for the first time.

The word was maybe used to indicate a Greek sweet that recalled in its shape the great pharaoh’s of the IV dynasty, funeral monuments.
In the word maybe there still is the reminiscence of the word “mer” that, according to a greatly diffused opinion could derive from the verb “ias” that means to raise.