Elian is a unisex Welsh name. St. Elian or Eilian has a sacred well consecrated to him (ffynnon eilian) where it could be from eilio meaning a moment in time, it could also be related to the Celtic root word meaning sun, it is also a Cornish and a Breton name.
Meaning & History. From a surname which was derived from a Cornish place name meaning "homestead on the hill".
Trevelyan is a Welsh and Cornish surname derived from a place-name which originally meant "farmstead 'trev' or Tref (town in Welsh) of Elyan".
