mu

Everyday

1. Mu (μ, M) is the twelfth letter of the Greek alphabet, the Greek m. tree →
2. (science, maths) The symbol μ means micro-, one millionth: a μm (micrometre) is a millionth of a metre. tree →
3. (Mandarin, pinyin) Mù is a Mandarin syllable; with a falling tone it means tree or wood (木), and also eye (目); it sounds like moo to an English ear. tree →
4. (Japanese, Zen) Mu can mean nothing or not having. It is not an ordinary English word. tree →
5. In some stories, people chant mu as a sound with no meaning, like a magic word. tree →

In the lessons

In maths and science, μ is used for micro- and, for older pupils, for the average (the mean) and friction. In Mandarin lessons, mù (木) is one of the first characters children see: it looks like a tree. In cartoons, a cow says moo, not mu. Phrases: μm, mu-sign.

Examples

• Mu is a letter in the Greek alphabet. tree →
• The symbol μm means micrometre. tree →
• In Mandarin, mù means tree. tree →
• The Chinese character for tree, 木, is said mù. tree →
• Alpha, beta and mu are all Greek letters. tree →
• Bacteria are measured in μm. tree →
• ‘We must bow three times eastwards and say “Mu...mu...mu...”’ tree →

Note

Pronounced mew in English (for the Greek letter) and moo in Mandarin. A cow's sound is spelled moo, not mu.