fú — blessing; good fortune

Where it comes from

福 is built from 礻, the altar radical that marks characters to do with ritual and spirits, and a right side that early forms show as a wine vessel raised in offering. It is the single most written character in Chinese domestic life: painted on red diamonds of paper, cut from paper as a window flower, embroidered, printed on every red envelope. The upside-down custom turns on a pun. 倒 dào means inverted; 到 dào means to arrive. Hang the character the wrong way up and a visitor reading your door says 福倒了 — "the fu is upside down" — which is heard as 福到了, "fortune has arrived". It is a wish disguised as a mistake, and it is deliberate in almost every household that does it.