ChiramiWhy the kanji for rainbow has a bug in it (虹)
The kanji for rainbow is 虹 (niji). On the left is 虫, which means bug today but began as a snake, and on the right is 工, which gives the sound. In ancient China a rainbow was thought of as a living creature arching across the sky, so it was written with a creature’s kanji.
What the kanji say
虫 (mushi) began as a picture of a snake, a viper. Over time it became the sign for all sorts of small creatures, from insects and worms to things that creep and crawl. That’s why it turns up in the kanji for snake, 蛇 (hebi), frog, 蛙 (kaeru), and even octopus, 蛸 (tako).
工 (kou) means craft or work, as in 工場 (koujou), a factory. In 虹 it’s there only for its sound: in old Chinese it was pronounced much like the word for rainbow.
Where it really comes from
This time the video’s story is real history. The oldest form of 虹, on Shang-dynasty oracle bones more than 3,000 years old, is a picture of an arched creature with an open-mouthed head at each end, something like a two-headed dragon or serpent. People saw a band of colour reaching down to a river and imagined a beast bending down to drink.
Later, the picture was replaced by a sound-and-meaning pair: 虫 for the creature, and 工 for the sound. Even then the old idea stayed: the Shuowen Jiezi, a Chinese dictionary from around 100 CE, describes the rainbow as “shaped like a creature”.
How to use it
見て、虹が出てるよ！
Mite, niji ga deteru yo!
Look, there's a rainbow!
雨上がりに虹がかかった。
Ameagari ni niji ga kakatta.
A rainbow appeared after the rain.
虹は七色だと言われています。
Niji wa nanairo da to iwarete imasu.
Rainbows are said to have seven colours.
虫が苦手です。
Mushi ga nigate desu.
I'm not good with bugs.
- Rainbows “come out” or “hang”: 虹が出る (niji ga deru) and 虹がかかる (niji ga kakaru) are the usual ways to say a rainbow appears.
- In Japan, a rainbow has seven colours, 七色 (nanairo), and 虹色 (nijiiro) means rainbow-coloured.
- 虫 describes people too: 泣き虫 (nakimushi) is a crybaby, 弱虫 (yowamushi) a coward, and 本の虫 (hon no mushi) a bookworm.
Words with the same kanji
| Word | Reading | Meaning |
|---|---|---|
| 虹色 | nijiiro | rainbow-coloured |
| 虫 | mushi | bug, insect |
| 昆虫 | konchuu | insect |
| 虫歯 | mushiba | tooth decay, a cavity |
| 泣き虫 | nakimushi | crybaby |
| 弱虫 | yowamushi | coward |
Remember it
After the rain, a long snake (虫) made of colours stretches across the sky and bends down to drink from the river. That’s 虹. The 工 beside it just tells you how the old word sounded.
The kanji in this lesson
Tap Draw it to watch the stroke order. Numbers show where each stroke starts.