We usually place all non-obs/non-arch/non-obsc senses above obs/arch/obsc ones

@@ -36,3 +36 @@
-<misc>&obs;</misc>
-<s_inf>original meaning</s_inf>
-<gloss>mistakenly announcing a win without having all the requisite tiles</gloss>
+<gloss>unintentional rule violation accompanied by a penalty</gloss>
@@ -46 +44,3 @@
-<gloss>unintentional rule violation accompanied by a penalty</gloss>
+<misc>&obs;</misc>
+<s_inf>original meaning</s_inf>
+<gloss>mistakenly announcing a win without having all the requisite tiles</gloss>

I can live with it like this, but maybe it would be better split into two.

https://majandofu.com/mahjong-glossary-chonbo
https://ja.wikipedia.org/wiki/麻雀の反則行為#チョンボについて

The "original meaning" mahjong sense is certainly obsolete. The above references call this the narrow meaning (狭義) of the word.

The modern meaning of the word encompasses many different rule violations of varying severity. Notably, these violations must be unintentional; cheating and rule violations that are judged to be bad-faith are not considered chombo (and will probably result in expulsion from a parlor / tournament / etc.). 「イカサマとは異なりあくまで故意でない反則やミスなどが対象です。」

The penalty is usually a payment to the other players, but not always. The offending player may just be forced to forfeit their ability to participate in the hand (see 「その2. アガり放棄」)

The majandofu has this regarding the etymology:
中国語の錯和(ツァホウ＝誤ったアガり)、または冲和(チョンフォウ＝虚しいアガリ)から来ている言葉です。
In addition to 錯和 and 冲和, the above wikipedia reference also has 狆和. 

It seems likely to me that the kanji forms are restricted to the narrow meaning of the word. I'm not sure this meaning and the kanji forms are necessary to have in JMdict, but if we keep 錯和 then I think we should have 冲和 too.

Google N-gram Corpus Counts
| 錯和　　 |    869 |  1.2% |
| 冲和　　 |    343 |  0.5% |
| 狆和　　 |      0 |  0.0% |
| ちょんぼ | 12,046 | 16.3% |
| チョンボ | 60,467 | 82.0% |

@@ -5,0 +6,4 @@
+<ke_inf>&rK;</ke_inf>
+</k_ele>
+<k_ele>
+<keb>冲和</keb>
@@ -31,0 +36 @@
+<misc>&obs;</misc>
@@ -33,0 +39,8 @@
+</sense>
+<sense>
+<pos>&n;</pos>
+<pos>&vs;</pos>
+<pos>&vi;</pos>
+<field>&mahj;</field>
+<misc>&uk;</misc>
+<gloss>unintentional rule violation accompanied by a penalty</gloss>

mk
etymology seems unclear, Japanese dictionaries only have it as hiragana. might not actually be from Chinese.
adj-na in the nikk example ※ぽんこつ（1959‐60）〈阿川弘之〉二つの婚約「そうチョンボなことはせんだろう」

@@ -12,0 +13 @@
+<re_nokanji/>
@@ -16,0 +18,2 @@
+<pos>&vi;</pos>
+<misc>&col;</misc>
@@ -25,0 +29 @@
+<pos>&vi;</pos>

https://kotobank.jp/word/ちょんぼ-569628
https://en.wiktionary.org/wiki/錯和#Japanese

錯和	869	1.2%
ちょんぼ	12046	16.4%
チョンボ	60467	82.4%

@@ -3,0 +4,4 @@
+<k_ele>
+<keb>錯和</keb>
+<ke_inf>&rK;</ke_inf>
+</k_ele>
@@ -12,0 +17 @@
+<misc>&uk;</misc>
@@ -21,0 +27 @@
+<misc>&uk;</misc>