As Soulman said, many English names originate from ancient languages. It can be difficult to get an exact meaning for many names now. If you do a Google search for the name + origin you can get some possible meanings. My name, Kevin is a fairly common name in English speaking countries so I would think the meaning is well known. However if I do a Google search for "Kevin origin", the first site says it means "handsome beloved" the next says it means "gentle, lovable", while the third says it means "Beautiful at birth". I think I will take the first meaning :)

You can make up any name you like, a name doesn't have to have a meaning. If you like it, then it's good! Like my name for example, it has no origin. I like my unique name =)

in my opinion, many english names are ancient but still used. so dictionaris (especially, written for learners) focus on contemporary english. there r however other reasons for example Frensh, Schottish, Welsh or Irish names... all of them r used as english names though difference. you can find the meanings by using NAMES BOOKS which has been published for english parentes waiting for babies and you can find the history of the words as well

I think May is a good name.