\begin{definition}[Definition:Metric System/Length/Centimetre]
The '''centimeter''' (UK English: '''centimetre''') is the CGS base unit of length.
It was initially defined as <math>10^{-9}</math> the distance from the Earth's equator to the North Pole at sea level, that is, <math>\frac 1 {100}</math> the length of a meter.
\end{definition}