<entry id="2229179" stat="A" corpus="jmdict" type="jmdict">
<ent_corp type="jmdict">jmdict</ent_corp>
<ent_seq>1263090</ent_seq>
<k_ele>
<keb>弦月</keb>
</k_ele>
<r_ele>
<reb>げんげつ</reb>
</r_ele>
<sense>
<pos>&n;</pos>
<xref type="see" seq="2147030">上弦の月</xref>
<xref type="see" seq="1184860">下弦の月</xref>
<xref type="see" seq="1583170">半月・1</xref>
<gloss>half-moon</gloss>
</sense>
<info>
<audit time="2023-04-20 19:04:39" stat="A" unap="true">
<upd_name>Brian Krznarich</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>This is the first of many moon edits. Lots of apparent issues with half-moons and crescent-moons.  (Note, this term on it's own is not super-common compared to 下弦　and 上弦）。

There are so many mismarked crescent-moons that I was starting to wonder if the Japanese thought 半月 included crescents... (I believe they do not)

弦月 is apparently tied up in a popular anime character which breaks the image search. try 上弦の月 and 下弦の月 instead.

Here's another a site with diagrams specifically using various formulations of 弦月
https://tukihosi-tan.com/moon/2004/

https://ja.wikipedia.org/wiki/%E5%BC%A6%E6%9C%88
弦月（げんげつ）は、半月（はんげつ）の文学的な表現である
Wikipedia xref for 弦月 is English "Half Moon".
In moon phases:
新月（朔。0°=0）
上弦（90°=7）
満月（望。180°=14）
下弦（270°=21）
半月（弦。上弦と下弦の総称） (半月 is a generic name for the waxing and waning half-moons)

nikk: either the waxing half-moon, the waning half-moon, or 弓張り月 (also a half-moon)
げん‐げつ【弦月】
〘名〙 上弦または下弦の月。ゆみはりづき。彎月(わんげつ)。

Another ref, straight to 半月:
https://kotobank.jp/word/%E5%BC%A6%E6%9C%88-491742
普及版 字通 「弦月」の読み・字形・画数・意味
【弦月】げんげつ
半月。
字通「弦」の項目を見る。

Since 半月 means 15 days/half-a-month, the ngrams crush this.  But I get the impression that this term in particular is common when talking about lunar cycles specifically. (I am sure 半月 is readily comprehensible though, perhaps moreso).


https://ja.wikipedia.org/wiki/%E5%BC%A6%E6%9C%88
英語でも、日本語での半月同様、一般的には half moon（または half-moon）というが、月相に基づく天文学用語としては quarter moon という。上弦の月は first quarter moon で、下弦の月は last quarter moon （または third quarter moon）である。

more notes on the xrefs.</upd_detl>
<upd_refs>Scroll down, picture of all moon phases and associated terms
https://www.arachina.com/lifestyle/moon-calendar-2022-march.htm
Here is what it says:
New Moon (0%): 新月、朔月
Waxing? Crecent: 三日月、眉月
Half:  上弦の月、引張り月、
2/3rds: 十三夜
Full: 満月、十五夜、望月
Waning? 2/3rds: 居待月
2/3rds: 二十三夜、下弦の月、下の弓張り、
WaningCrescent；下弦後の三日月、有明の月

The "bow" moons, 弦 and 引 invoke the image of a bow with a taught bowstring

Here's a picture showing that imagery:
https://weathernews.jp/s/topics/202005/260335/

Here's a reference specifically for 弦月 as "half-moon", which includes 上弦 and 下弦 as well as 弓張り月 listed as an explicit synonym.
https://en.wiktionary.org/wiki/%E5%BC%A6%E6%9C%88
Appears to be a learned borrowing from Chinese 弦月 (xiányuè). First cited in a Japanese text in 1698.[1] May have been in use prior to this, considering that partial synonyms 上弦 (jōgen) and 下弦 (kagen) are attested already in the late 800s.[2][3]
弦げん月げつ • (gengetsu) ←げんげつ (gengetu)?
[from 1698] half-moon 
Synonym: 弓張り月 (yumiharizuki)</upd_refs>
<upd_diff>@@ -12 +12,6 @@
-&lt;gloss&gt;crescent moon&lt;/gloss&gt;
+&lt;xref type="see" seq="2147030"&gt;上弦の月・じょうげんのつき&lt;/xref&gt;
+&lt;xref type="see" seq="2147030"&gt;上弦の月・じょうげんのつき&lt;/xref&gt;
+&lt;xref type="see" seq="1184860"&gt;下弦の月・かげんのつき&lt;/xref&gt;
+&lt;xref type="see" seq="1184860"&gt;下弦の月・かげんのつき&lt;/xref&gt;
+&lt;xref type="see" seq="1583170"&gt;半月・はんげつ・1&lt;/xref&gt;
+&lt;gloss&gt;half moon&lt;/gloss&gt;</upd_diff>
</audit>
<audit time="2023-04-20 19:25:25" stat="A" unap="true">
<upd_name>Brian Krznarich</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>hyphen, you learn something every day...</upd_detl>
<upd_diff>@@ -17 +17 @@
-&lt;gloss&gt;half moon&lt;/gloss&gt;
+&lt;gloss&gt;half-moon&lt;/gloss&gt;</upd_diff>
</audit>
<audit time="2023-04-21 02:02:28" stat="A">
<upd_uid>jwb</upd_uid>
<upd_name>Jim Breen</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_detl>Happy to leave cresent off this one, although some JEs have it.</upd_detl>
</audit>
<audit time="2023-04-21 20:15:36" stat="A">
<upd_uid>robin1354</upd_uid>
<upd_name>Robin Scott</upd_name>
<upd_email>...address hidden...</upd_email>
<upd_diff>@@ -12,3 +12,3 @@
-&lt;xref type="see" seq="2147030"&gt;上弦の月・じょうげんのつき&lt;/xref&gt;
-&lt;xref type="see" seq="1184860"&gt;下弦の月・かげんのつき&lt;/xref&gt;
-&lt;xref type="see" seq="1583170"&gt;半月・はんげつ・1&lt;/xref&gt;
+&lt;xref type="see" seq="2147030"&gt;上弦の月&lt;/xref&gt;
+&lt;xref type="see" seq="1184860"&gt;下弦の月&lt;/xref&gt;
+&lt;xref type="see" seq="1583170"&gt;半月・1&lt;/xref&gt;</upd_diff>
</audit>
</info>
</entry>