Definition of "clayen"

It is difficult to see why silveren should have been dropped, and brazen and golden retained. Better return to stonen and clayen and yarnen, than lose golden and its fellows.

1870, Richard Grant White, Words and Their Uses, Past and Present: A Study of the English Language, page 261

Encircling in turn the best bearing trees, they drank from “clayen-cups,” and poured part of the contents on the ground under the trees. And while they wassailed the trees they sang:— “Here's to thee, old Apple tree! Whence thou mayst bud, and whence thou mayst blow, And whence thou mayst bear Apples enow! Hats full! caps full, Bushel—Bushel—sacks full, And my pockets full too.”

2016, Alice Morse Earle, Old-Time Gardens, Newly Set Forth, Krill Press via PublishDrive