micro

Everyday

1. Micro means very small: «a micro farm», «micro plastics». tree →
2. As a prefix, micro- makes words about tiny things: microscope, microchip, microphone, microwave. tree →
3. (science) In measurement, micro- means one millionth, as in micrometre or microgram. tree →
4. (informal) A micro is a short name for a small computer, a microwave oven, or the BBC micro:bit used in schools. tree →

In the lessons

In science lessons micro- names tiny things (micro-organisms); in computing, children program the micro:bit. In everyday talk «micro» means tiny. Phrases: «micro:bit», «micro scooter», «micro-organism».

Examples

• We programmed the micro:bit to show a heart. tree →
• A microscope helps you see micro-organisms. tree →
• My little brother has a micro scooter. tree →
• Micro means very small. tree →
• Microplastics are tiny bits of plastic in the sea. tree →
• A micrometre is one millionth of a metre. tree →
• (informal) Put the soup in the micro for two minutes. tree →
• The micro-chip in the dog's neck has its owner's details. tree →

Note

As a prefix it often joins the word: microscope, microphone. In maths and science micro means one millionth: 1 micrometre is 0.000001 m. The opposite size prefix is «macro» (large) or «mega» (a million).