Question

青 あお、あお-、あお.い blue, green 4 589 8 174 あお・あおへん 形声 Phonetic The last time I saw a blue moon was in my youth when I was growing up.

Accepted Answer

セイ、ショウ お 青(あお): (1) blue (2) green (3) green light (4) black (horse coat color) (5) immature; unripe; young青年(せいねん): youth; young man青春(せいしゅん): youth; springtime of life; adolescent青少年(せいしょうねん): youth; young person青い(あおい): (1) blue; green (2) pale (3) unripe; inexperienced真っ青(まっさお): deep blue; ghastly pale青白い(あおじろい): (1) pale; pallid (2) bluish-white 1 月: month; moon 青 8 (none) blue Once in a blue moon refers to a rare event. But originally "blue moon" refers to a full moon, in other words a fully grown-up moon. Whether once a month is rare or not depends on what we´re talking about, but that happens to be the origin of the expression.

Kanji	青
Onyomi	セイ、ショウ
Kunyomi	あお、あお-、あお.い
Nanori	お
English	blue, green
Examples	青(あお): (1) blue (2) green (3) green light (4) black (horse coat color) (5) immature; unripe; young 青年(せいねん): youth; young man 青春(せいしゅん): youth; springtime of life; adolescent 青少年(せいしょうねん): youth; young person 青い(あおい): (1) blue; green (2) pale (3) unripe; inexperienced 真っ青(まっさお): deep blue; ghastly pale 青白い(あおじろい): (1) pale; pallid (2) bluish-white
JLPT Level	4
Jouyou Grade	1
Frequency	589
Components	月: month; moon
Number of Strokes	8
Kanji Radical	青
Radical Number	174
Radical Strokes	8
Radical Reading	あお・あおへん
Traditional Form	(none)
Classification	形声 Phonetic
Keyword	blue
Koohii Story 1	The last time I saw a blue moon was in my youth when I was growing up.
Koohii Story 2	Once in a blue moon refers to a rare event. But originally "blue moon" refers to a full moon, in other words a fully grown-up moon. Whether once a month is rare or not depends on what we´re talking about, but that happens to be the origin of the expression.

Green Blue Young Youth Moon 青 Unripe Pale