47. The "River" Radical: 川
The three-stroke 川 radical is closely related to the autonomous kanji of the same shape:
川 (48: river)
Just as that kanji carries the Joyo kun-yomi かわ, we can refer to the 川 radical as かわ, or as "river" in English.
Nelson proposes another name for the radical:
さんぼんがわ (三本川: "three-stroke river")
This term emphasizes that one is referring to 川, not to the eight-stroke 河 (river), also carrying the Joyo kun-yomi かわ. I didn't know why anyone would need to make such a distinction, as 河 isn't a radical. I was therefore intrigued to hear that people do this to differentiate not between radicals but rather between proper nouns. For example, if one’s name is かわかみ, one is likely to say that the かわ part should be written with さんぼんがわ (川) or さんずいのかわ (河), producing 川上 or 河上, respectively. (I just finished listening to a novel by Mieko Kawakami and kept wondering how her surname is written. It's 川上.)
Our radical maintains its shape in the following kanji:
州 (304: province, state; sandbank)
By contrast, 川 gets bent out of shape in this one:
巡 (1374: to go around)
Here we're seeing the cool-looking variant form 巛 known as まがりがわ (曲がり川: "curving river").
The variant is older than 川 when it comes to renderings of the 川 kanji. Perhaps for this reason, dictionaries such as Kangxi and Kanjigen call 巛 the primary shape of the radical, with 川 as the variant. This makes no sense to me, so I've gone with 川 as the main form of radical 47.
Just like that, we've encountered all three Joyo kanji featuring radical 47 when it's on duty.
Photo Credit: Corey Linstrom
Matters of Etymology
Henshall provides a simple etymology of 川 in his newer edition, calling it a pictograph of "water flowing between two river banks."
The more elaborate 州 (304: province, state; sandbank) has a slightly more involved etymology. Henshall says it depicts an "islet or sandbank in a river." Well, originally there was just one islet, but the number later expanded to three. The meaning of the character also broadened, in that 州 came to symbolize large areas of land, such as states or provinces, he says.
As for 巡 (1374: to go around), that combines two radicals, the other being 辶, the "movement" radical. Henshall notes that one researcher takes the 巛 to contribute meaning (river, of course!), yielding the overall sense "go round following a set route." Another scholar sees the 巛 as the phonetic with the associated sense "see, gaze at," leading 巡 as a whole to mean "walk while looking." That expert treats "go round" as loan usage.