ekmetresai

Hello, everyone.

I'm translating a work by Michel Serres (Hermes II) from French to English. The author has this footnote with little explanation. He is discussing the origin of geometry:

"The term ekmetresai doesn't belong to the lexicon of pure geometry."

The word is probably Ancient Greek. I would guess it has something to do with measuring, but I would appreciate any more precise information you could give.

Thanks in advance.