This week's character is a nice, simple one — 水 (shuǐ), which means "water" (check out 水 stroke order on Wikimedia Commons for an animated GIF showing how to write it). Like last week's 瓜/guā, it's a radical as well as a character in its own right.
Perhaps the most common occurrence of 水 on the Chinese menu — and indeed the context in which I first encountered it — is as 水煮 (shuǐ zhǔ). Although this translates literally as "water-cooked", the widely-available dishes of 水煮牛肉 (shuǐ zhǔ niú ròu) and 水煮魚片 (shuǐ zhǔ yú piàn) are almost entirely the opposite of what you might expect from "boiled beef" or "boiled fish" — the 水煮 method is actually a deliciously spicy and fiery Sichuan cooking style (of which more on Friday).
Another common use for 水 is in 口水雞 (kǒu shuǐ jī), or "mouthwatering chicken". This is another Sichuan dish, served cold. (Incidentally, if you've seen "saliva chicken" on those wackily-translated not-exactly-perfect-English menus, this is what they mean.) Note that the tone sandhi rule I mentioned on Monday applies to both 口水雞 and 水煮, since they feature two third tones in succession.
The most usual way 水 looks when used as a radical is as three disconnected strokes sticking out from the left-hand side of the character; however, in some fonts these strokes are connected to each other (screenshot). Also, a few characters incorporate the radical in a different way, for example 泰 (tài), which puts it on the bottom rather than on the left, and keeps the standard form rather than transforming it into three strokes. 泰 is short for "Thailand"; you might see it on a menu as, for example, the common dim sum dish of 泰式鳳爪 (tài shì fèng zhǎo), which means Thai-style chicken feet (literally "Thai-style phoenix claws").
Here are some other characters that use 水 as a radical:
|汁||zhī||juice/sap/gravy; often seen as 姜汁 (jiāng zhī), which indicates that something's in a ginger sauce.|
|沙||shā||sand/granular/powdery; see 金沙玉米 (jīn shā yù mǐ, or "golden sands corn"), and also note that 沙 is used phonetically in 沙爹 (shā diē), which means "satay". Be sure not to confuse it with 炒 (chǎo/stirfried), which is similar but has a different radical.|
|河||hé||used alone and as 河粉 (hé fěn) to refer to ho fun noodles.|
|油||yóu||oil/fat/grease; used as e.g. 紅油 (hóng yóu), meaning chilli oil (literally "red oil").|
|泥||ní||mashed; e.g. as 蒜泥 (suàn ní), which is mashed garlic.|
|海||hǎi||sea/ocean; most often seen on menus as 海鮮 (hǎi xiān), literally "ocean fresh", meaning seafood, but as john points out in a comment on an earlier post, it also turns up as 上海 (Shànghǎi).|
|涼||liáng||cool/cold; commonly seen as 涼菜 (liáng cài), meaning cold dishes such as cucumber salads.|
|湯||tāng||soup, e.g. 酸辣湯 (suān là tāng) — hot and sour soup.|
|水:||shuǐ||radical 85 (水/氵/氺)||Cantodict||MandarinTools||YellowBridge||Zhongwen|