12. The "Eight" Radical: 八

Though the two-stroke 八 radical looks quite simple, it presents a type of confusion that few other radicals do. That is, the kanji means "eight," but the radical number is 12! Moreover, these are two of the most common kanji featuring the radical:

八 (66: eight; many; specific time of day)

六 (76: six)

We haven't gotten very far, and already I've mentioned 2, 6, 8, and 12! Oh, and 66 and 76! It sounds like the start of a great math problem! 

Photo Credit: Eve Kushner

A Nagoya shop specializing in bento boxes is named 八起 (やおき). The sign features a lovely rendering of 八, beautifully complemented by the two strokes at the bottom of 起.

Photo Credit: Ulrike Narins

This license plate bears the name 八王子 (はちおうじ), a city in Tokyo.

Photo Credit: Eve Kushner

This izakaya (pub) in the Ginza section of Tokyo is called 
傳八 (でんぱち). The non-Joyo 傳 is the variant form of
伝 (to transmit).

What Shapes Can the 八 Radical Have?

In the license plate above, the right-hand side of 八 features a hook, whereas the kanji is more symmetrical in the izakaya name. The kanji shape depends on the font.

Nelson indicates that the symmetrical shape is the primary way of rendering 八 and calls the hooked kind a variant. Indeed, old images reflect that the character was symmetrical from the start.

In a second variant, 八 turns on its head. Check out the two strokes atop this kanji:

兼 (850: concurrent; to serve two functions; cannot possibly do; previously)

Photo Credit: Corey Linstrom

The name 六芸神 (ろくげいしん) might feature the cutest use of the 八 radical I've ever seen! Japanese Wikipedia says that this display in the Asakusa section of Tokyo dates to 1996 and that the six bronze gods take after great performers who actually lived. The name 六芸神 reflects that there are six (六) performing (芸) gods (神). This bit of creativity has no connection to Shinto or its deities.

What Is the 八 Radical Called?

The name of our radical depends on its location. When it comes to the autonomous 八 kanji, we can call the 八 radical はち. That is simply the Joyo on-yomi of the character.

The same name applies when the 八 radical sinks to the bottom of a kanji:

六 (76: six)

具 (265: tool; ingredients (of soup, curry, etc.); to have what’s necessary)

共 (460: shared, together, both; including; communism)

典 (552: reference book; important book; rule; model; ceremony)

兵 (578: soldier; military) 

If the radical instead crowns a character, we can use the name はちがしら. We've seen that the crowning radical is inverted in 兼 (850: concurrent). Here's a character in which 八 is at the top and stays upright:

公 (277: public; official; common (in math); fair)

In はちがしら, the がしら is the voiced version of かしら, a position name for a radical that crowns a character. (One more commonly hears かんむり for this position name.)

A third name for the 八 radical is just は. That seems so short as to be unclear!

What Does 八 Mean in Characters?

Henshall says in his newer edition that early forms of the autonomous character 八 depict "splitting" or "dividing" and that the ancient Chinese then borrowed 八 phonetically to represent "eight." He notes that the component still indicates "splitting" and by extension "disperse, away, out." But in his etymologies of all the kanji featuring this on-duty radical (aside from 八 itself), I've found that to be true for only one character:

公 (277: public; official; common (in math); fair)

Henshall presents multiple interpretations of 公. In one view, the 八 meant "divide, open up," and the 口 originally at the bottom represented "enclose, surround." Together these halves may have meant "open up a physical area" or "open up something enclosed (or) kept by individuals." These senses extended to "open up" and then "public; fair (distribution)."

In his analyses of the other kanji featuring this on-duty radical, he hardly mentions 八. It's that inconsequential semantically.

Which Other Radicals Resemble 八?

At Nikko National Park (日光国立公園, にっこうこくりつこうえん), the following sign features two dragons! The first is in 竜頭 (りゅうず: dragon head), the other in 滝 (たき: waterfall), which features a dragon (竜) in water (氵)!

Photo Credit: Tomohiro Matsuzaki

The sign also presents our radical in 公, as well as a look-alike radical in 光 (116: light). That latter kanji instead features radical 10, the "legs" radical 儿.

As for 頭 (186: head), that may seem to contain our radical on the bottom right. In reality, 頭 is classified under radical 181, the "big shell" radical 頁.

Unrelated to the waterfall sign, another radical that closely resembles 八 is 人, radical 9 ("person").