Gild is a verb meaning to cover with a layer of gold. It’s often used in the participial-adjective form gilded, meaning covered with a layer of gold, and it’s usually figurative. Guild is a noun meaning an association of people with the same interests, trade, or pursuits. It can also be a verb meaning to form a guild, but this sense is rare.
The common expression to gild the lily means to unnecessarily adorn something that is already beautiful. It derives from Shakespeare, though the quote actually goes, “To gild refined gold, to paint the lily.“
Examples
These writers use gild well:
The walls are filled with miniature portraits, mirrors with gilded frames and old family photographs. [Montreal Gazette]
They are gilded ages, perhaps; yet every such age gilds not the lily but the tulip … [The Nation]
It is not always just nostalgia that gilds the past. [Guardian]
And these writers use guild well:
Originally settled by monks, the small town of Hoegaarden—to the east of Brussels—had its own guild of brewers by the 1500s. [Manawatu Standard]
Diplomatic and military historians, respectful of the guilds of which they regard themselves as honorary members, tend not to pose moral questions too sharply. [The Wall Street Journal]

