This saintly name--she was the mother of St. Augustine--plummeted after the double whammy of Lewinsky and the demise of Friends.

The sort of oh-so-French name that's falling out of favor now.

Like many short forms now popular as full names in the Netherlands, Coen—also spelled Koen—originated as the diminutive of the more old-fashioned Coenraad, the Dutch Conrad. In this case, it would be pronounced as KOON, with a short oo sound.
Alternatively, it may be used in the US as a variation of Cohen, which stems from the Jewish surname designating a priest, and thus pronounced as CO-uhn. Additionally, it may also relate to the Irish surname McCown ("of Connacht") or to the Australian place name, Coen, meaning "thunder" from its Indigenous roots.

A short form popular in the Netherlands, though in the U.S. Koen and Coen are easily confused with Cohen, the Jewish surname meaning "priest" which has recently gained currency as a first name. The Dutch pronunciation is more like "coon."

Dashing and highly unusual variation does the feminine original one better by sounding both more modern and more usable. Or you can spell it Monaco and call it a place name.

What child wouldn't like a name that was a synonym for cool?

Extremely unusual ella-ending choice.