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millimetre

British  
/ ˈmɪlɪˌmiːtə /

noun

  1.  mm.  one thousandth of a metre

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The dust grains around R Doradus are typically only about one ten-thousandth of a millimetre across.

From Science Daily • Jan. 12, 2026

Other leagues, including the top flights in Germany, Spain and Italy, have gone back to offside by the millimetre.

From BBC • Jan. 4, 2026

It sounds like something from the distant future, but nanotechnology - engineering at a scale of millionths of a millimetre - is already used in lots of everyday real-life tech.

From BBC • Jan. 2, 2026

Mr Botero claims that less than a millimetre of this coating will provide the same insulating effect as 40 millimetres of foam.

From BBC • Oct. 31, 2024

It has been found that the “carbons” in drills can safely be subjected to a pressure of over 60 kilograms per square millimetre, and a speed of 25 metres per second.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 4 "Diameter" to "Dinarchus" by Various