It does look French, because it comes from the French language. There's a place in Normandy, France called Évreux. Some folks from Évreux migrated to England during the Norman Conquest in 1066, and when they got there, people referred to them as d'Évreux, which means "from Évreux." The spelling eventually evolved into Devereux, Devereaux, and other variations.
The name Devereux is actually very rare in France. It's far more common in England and Ireland, where people called Devereux have been living for nearly 1,000 years. So even though the name comes from the French language, most folks with this surname have English or Irish ancestry, and many of them pronounce it like "Devericks."
I have Devereux ancestors from Ireland