You need a unicode-enabled browser with japanese fonts installed to see the Japanese in this write-up.
Japanese is romanised as Hepburn, Chinese is romanised as pinyin. Kanji entry would be impossible without tongpoo's Unicode converter. Sadly, Mozilla 1.7 does not properly render Unicode and glyphs may display incorrectly.

The Japanese word transliterated into English as 'sushi' may be written in hiragana as すし, but there are a plethora of kanji that are or have been used. Here follows an incomplete list, but all are read as 'sushi すし' in Japanese.

寿司 shòusī is a pair of words chosed for their sound rather than their meaning ('longevity-manage'). There exists a list of less frequently used combinations of kanji which follow similar lines: 寿志, etc. Please see ateji for an explanation of this practice.

鮨 zhī is a Classical Chinese word meaning 'fish sauce'. The Ěr yǎ gives the following definition 《爾雅 • 釋器》: 「肉謂之羹、魚謂之鮨。」 ròu wèi zhī gēng, yú wèi zhī zhī. "(That made from) meat is called 羹, (that made from) fish is called 鮨".
鮨 yì is a modern word which is written identically and refers to any perch-like fish.

鮓 zhǎ is another Classical Chinese word, but it means 'preserved fish'. This kanji is more frequently seen in writings from the Edo period, but is not now in current use. The original Chinese refers to fish pickled with salt and rice: 「鮓滓也以鹽米釀之加葅、熟而食之也。」 zhǎ zǐ yě yǐ yán mǐ niàng zhī jiā jū, shú ér shí zhī yě. which translates as, "鮓滓 is fish pickled with salt and rice; when fully fermented, it may be used as food". This dish has disappeared from Chinese cuisine but is preserved in Japan as narezushi なれ寿司.
鮓 zhà is a modern Chinese word referring to a type of bony fish.

鮺 and 䱹* are merely different ways of writing the character 鮓. 鮺草灘 Zhǎcǎotān is the name of a place in Sichuan 四川 and is really the only reason that this variant character exists in modern dictionaries.

䰼* xín is minced fish cured in salt (also written 𩷒*).

As an aside, modern Chinese calls salted fish 鹹魚 xiányú, while sushi is written 壽司 shòusī, like the Japanese ateji.

* Internet Explorer 6 unfortunately does not have glyphs for some of the Chinese characters in this write-up, even with the densely populated Arial Unicode font installed. Please refer to code points 4C79 zhǎ, 4C3C xín and 29DD2 xín at to see what the question marks, dots and boxes refer to. There should be no problems with Mac OS X except for the final 32-bit extended unicode character (thanks generic-man).