hellier
One who heles or covers; hence, a tiler, slater, or thatcher.
obsolete
he that covereth the house with tile or slate, is from thence commonly called a hellier
Where it comes from
From Middle English heliere, helyare, helyer, hillyer, equivalent to hele (“to conceal, hide; to cover”) + -ier.
Adapted from the Wiktionary entry hellier (CC BY-SA 4.0).