Meaning: Vale is an English word referring to a tract of land lying between two hill ranges sometimes with a river running through it; it's been used as a poetic word for a valley. It's derived from Old French val from Latin vallis meaning "valley".
Vale also means "farewell" from Latin vale; it's found in the Latin phrase ave atque vale meaning "hail and farewell".
Vale also refers to mortal life on earth; the expession this vale of tears refers to the world and the sorrows felt through life.
Spelled Vail, it has several possible meanings. It could be from Old French valoir meaning "to be worth" from Latin valeo (I am worth). It was used as an archaic word for "profit, proceeds".
Vail is also an aphetic variant of avail meaning "to be of use, of value" also from Latin valere (to be worth).
Another possible origin is from Old French veille from de la veille meaning "of the watch, watchman" from Latin vigilia (watch, wakefulness).
Vail could also be derived from Old French veel meaning "calf", a surname derived as an occupational name for someone who took care of calves or a nickname for someone who resembled a calf, or possessed characteristics of the animal.
Vail could also have originated as a nickname an older sibling or an older person from Old French viele meaning "old".
It could also be tied back to Old French val meaning "valley", making it a variant spelling of Vale.