80. The "Mother" Radical: 毋
I have to focus intently to distinguish these three shapes:
毋 母 毎
Actually, I don't really know the first, except as the bottom of the third one. Here are the vitals on all three characters:
毋 (なか•れ: must not; do not), a non-Joyo kanji
母 (203: mother; home; base material)
毎 (206: every; at an interval of)
The four-stroke 毋 is radical 80, and the other two shapes are Joyo kanji featuring this on-duty radical. Now we can make sense of these radical names:
1. なかれ, referring to the kun-yomi of 毋
2. ははのかん, corresponding to 母の毋, which simply means "the radical in 母"
3. はは, alluding to the Joyo kun-yomi of 母
Nelson provides one other name, an inversion of the second one:
4. かんのはは, referring to the top of 貫 (a obsolete unit of weight (approx. 3.75 kg or 8.3 lbs))
In English we can call the radical "mother" or "not," drawing on the definitions of the first two kanji. "Mother" is the primary name simply because, as a Joyo kanji, 母 is more recognizable than 毋.
Photo Credit: Eve Kushner
The 毎 kanji leads the way in a sign with these terms:
毎週 (まいしゅう: each week)
月曜 (げつよう: abbrev. of 月曜日 (げつようび: Monday))
定休日 (ていきゅうび: fixed day off)
So the establishment is closed every Monday.
Etymologies of Three Kanji
Our radical is on duty in just three Joyo kanji. Here they are, along with Henshall's etymologies from his newer edition:
母 (203: mother; home; base material)
In this pictograph of a "woman" (女), the shapes of the breasts and nipples are exaggerated.
毎 (206: every; at an interval of)
The Traditional shape is 每, which some scholars see as depicting "mother with hairpin." Others view 每 as a "plant," calling 母 the phonetic with the associated sense "abundant." Henshall sides with the latter camp but never notes that that would make 母 both the radical and the phonetic. He identifies "each, every" as borrowed usage.
毒 (559: poison; harm)
The character doesn't break down as I'd expect. To my surprise, the bottom part isn't 毋 but rather 毐 (士 over 毋), a non-Joyo character meaning "indecent act." That shape serves as the phonetic with the associated sense "harm," says Henshall. The top means "plant." Together the parts yield "plants to harm people," which is to say "poison." Again, this analysis acknowledges nothing about the 毋 radical and its duplicated role as part of the phonetic. (Incidentally, Kanjigen presents 毒 as having no phonetic.)
Photo Credit: Eve Kushner
This sign at a sheep farm incorporates 毒 (poison; harm):
手の消毒をお願いします。
Please disinfect your hands.
手 (て: hand); 消毒 (しょうどく: disinfection);
お願いします (おねがいします: please, stated in humble language)
The bottom row tells you where the farm is:
神戸 (こうべ: Kobe)
市立 (しりつ: city)
六甲山 (ろっこうさん: Rokko Mountains)
牧場 (ぼくじょう: farm)
The whole farm is actually called 神戸市立六甲山牧場.