Deve looks like D'Eve, "(son) of Eve". But there is a French surname Deve, with acute accents over the Es and pronounced dayvay. This is from an old French word desve (accent on the second E), meaning "mad". Pitot could be another of those names meaning "caring, pitying", there are several with different endings, Piton, Pitet, etc. The medieval French must have been a caring people! Peto - is it French? it's an English surname certainly (from Poitou, France); also Hungarian, meaning "Peter". If French it is probably a nickname for someone with intestinal problems. I'll leave it at that.