ZEST, the woody thick skin, quartering the kernel of a walnut; prescribed by some physicians, when dried and taken with white wine, as a remedy against the gravel.
Zest is also used for a chip of orange or lemon peel; such as is usually squeezed into ale, wine, &c. to give it a flavour; or the fine ethereal oil which spurts out of that peel on squeezing it.