Millimeter

How to spell millimeter

10 letters · 4 syllables

How to pronounce millimeter

Say the part in capitals loudest.

What does millimeter mean?

1. nounA metric unit of length equal to one thousandth of a meter.

Millimeter in a sentence

• The engineer measured the gap to the nearest millimeter.

• A single millimeter of rainfall was recorded overnight.

Where does millimeter come from?

Language of origin: Latin

This word is a compound built from two pieces with classical roots. The first part, milli-, comes from the Latin mille, meaning 'thousand', though in the metric system it was adopted to signal one thousandth of a unit rather than a thousand of them. The second part, meter, descends from the Greek metron, meaning 'a measure', which passed into French as metre when the metric system was formalised after the French Revolution in the 1790s. English speakers in the United States settled on the spelling 'meter', so the thousandth-of-a-metre unit became 'millimeter' there. The doubled l in milli- traces straight back to the Latin mille, and remembering that 'thousand' connection is the surest way to avoid dropping a letter when you write it.

How the word is built

• milli- (from Latin mille: thousand, here meaning one thousandth)
• meter (unit of length)

British and American spelling

Millimeter is the American spelling. British English spells it millimetre.