Definition:Metric System/Length/Centimetre

Definition
The centimeter (UK English: centimetre) is the CGS base unit of length.

It was initially defined as $$10^{-9}$$ the distance from the Earth's equator to the North Pole at sea level, that is, $$\frac 1 {100}$$ the length of a meter.

Linguistic Note
The spelling centimetre is the one adopted by the International Bureau of Weights and Measures. Centimeter is the variant used in standard American English, but see the linguistic note on meter.