毫米

• Pinyin: háo mǐ
• Hanzi breakdown: 毫 = 高 (tall) variant + 毛 (hair) — something as fine as a hair, meaning tiny or one thousandth; 米 = pictograph of rice grains, borrowed for the metric unit 'metre'

Meaning

Millimetre. A unit of length equal to one thousandth of a metre, used for precise measurements.

Used in science, engineering, weather reports for rainfall, and everyday precise measurements. The prefix 毫 means 'one thousandth' and appears in other metric units like 毫升 (millilitre) and 毫克 (milligram). Common in technical and scientific contexts.

Examples

1. 昨天的降雨量达到了五十毫米。 Yesterday's rainfall reached fifty millimetres.
2. 这张纸的厚度只有零点一毫米。 The thickness of this paper is only 0.1 millimetres.
3. 请用毫米来测量这条线的长度。 Please measure the length of this line in millimetres.

Usage Guide

Context: science, weather, measurement

Tone: technical

Do Say

• 今天的降雨量是二十毫米。(Today's rainfall is twenty millimetres.)
• 这个零件的精度要求是零点五毫米。(The precision requirement for this part is 0.5 millimetres.)

Don't Say

• 我家离学校有三毫米 (Don't use 毫米 for large distances — use 米 or 公里; 毫米 is only for tiny measurements)

Origin & History

毫 (háo, one thousandth/fine hair) + 米 (mǐ, metre) — one thousandth of a metre, following the metric prefix system.

Cultural Context

Generation: All ages

Social background: Universal