What does decimeter mean?
A decimeter is a metric unit of length equal to one tenth of a metre, or ten centimetres. The prefix 'deci-' comes from the Latin decimus, meaning 'tenth', so the name literally means 'a tenth part of a metre'. Although it is an official SI-recognized multiple of the metre, the decimeter is used far less often in daily life than the centimeter or the millimeter; most speakers find it more natural to say 'ten centimeters' than 'one decimeter'. It does appear regularly in scientific and technical writing — for example, in describing radio wavelengths in the decimetric band or volumes in cubic decimeters — and it is taught in schools as part of learning the decimal structure of the metric system. British English typically spells the word 'decimetre', following the convention of ending metric units with '-metre' rather than the American '-meter'.
nounA metric unit of length equal to one tenth of a metre (10 centimetres). It is spelled 'decimetre' in British English.
- A unit of length in the metric system equal to one tenth of a metre (10 centimetres).
"The seedlings were spaced about one decimeter apart in the tray."
"The fish measured nearly three decimeters from nose to tail."
"Convert the volume to cubic decimeters before recording it in the lab notebook."
Regular plural; British spelling takes the plural form 'decimetres'.
"The panel was cut to exactly five decimeters in width."
A decimeter sounds tiny, but stack ten of them and you've got a full metre — the prefix 'deci-' just means 'one tenth'.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of decimeter
The word 'decimeter' was formed in French as décimètre at the time of the late 18th-century introduction of the metric system, combining the Latin-derived prefix deci- ('tenth', from Latin decimus) with mètre ('metre', from Greek metron, 'measure'). It entered English shortly after, alongside other metric units such as the centimeter and millimeter. It shares its root with words like 'decimal', 'decimate', and 'decibel', all ultimately tracing back to the Latin numeral for ten, decem.
Related word forms
How decimeter is actually used
The word is relatively uncommon in everyday speech, where centimeters are preferred; 'decimeter' appears mostly in scientific, technical, and educational contexts, especially in measurements of wavelength (e.g., the decimetric radio band) and in some countries' school curricula.
Easily confused with decimeter
A decameter is 10 metres, whereas a decimeter is only a tenth of a metre — the two differ by a factor of 100 despite their similar spellings.