Other forms: millimetres
A millimetre is a thousandth of a metre. Ten millimetres, a millimetre thick, measured in millimetres.
It is the smallest unit marked on an ordinary ruler and the standard one in engineering drawings, where using centimetres is discouraged because the extra decimal place invites mistakes. Rainfall is measured in millimetres of depth. Note the American spelling millimeter, and that milli- means a thousandth.
1nounmillimetreA thousandth of a metre.
“The screw is only three millimetres wide, so you'll need a tiny screwdriver.”
millimetre is a unit of length.
Also accepted in games: millimeter
French millimetre is milli-, a thousandth, plus metre. Both parts come from the metric system of 1795.
French
millimètre
English, today
millimetre
From French millimètre, equivalent to milli- + metre.
Etymology from Wiktionary, CC BY-SA