To gild is to cover with a layer of gold. It word is often used in the participial-adjective form, gilded, which means covered with a layer of gold, and it’s usually figurative. Guild is a noun referring to an association of people with the same interests, trade, or pursuits. It also works as a verb meaning to form a guild, but this sense is rarely used.
The common expression to gild the lily means to unnecessarily adorn something that is already beautiful. It comes from Shakespeare, though the quote actually goes, “To gild refined gold, to paint the lily.”
The walls are filled with miniature portraits, mirrors with gilded frames and old family photographs. [Montreal Gazette]
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]
They are gilded ages, perhaps; yet every such age gilds not the lily but the tulip. [The Nation]
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]
It is not always just nostalgia that gilds the past. [Guardian]