-hay (also hays, hayes, etc.) is a place-name word-ending common in England. It derives from the Old English word hege or haga, Middle English heie, in Icelandic hagi, meaning "an enclosed field", and is from the same root as the English word "hedge", a structure which surrounds and encloses an area of land, from the Norman-French haie, "a hedge". Haw (from O.E. haga) and Hay (from O.E. hege) are cognate and both mean "hedge".
Examples
Cheslyn Hay, Walsall, meaning "a fenced or hedged enclosure", here perhaps around an ancient cromlech or burial-mound. Pipe Hayes ("hedges"), Erdington.
Derbyshire
The Findern Hays
Devon
Exeter
In the vicinity of Exeter: Floyer Hayes Northern Hay Southern Hay Shill Hay Fryers Hay Bon Hay Princesshay
Tiverton
In the vicinity of Tiverton: Moor Hayes, Cullompton Passmore Hayes Buck Hayes Rashleigh Hayes Gorn Hay Wid Hayes Moor Hayes, Washfield
See also
Hayes (surname), sometimes derived from this topological source
Sources
Johnston, Rev. James B., The Place-Names of England and Wales, London, 1915, p. 147