0 a unit of measurement equal to one thousandth of a mole (= a measure of the amount of a substance): --
The naturally occurring carbon dioxide level of the average horse is around 31 millimoles per litre.
Doctors found his sodium level was 184 millimoles per litre, compared with the normal 140.
Taxi drivers were found to have the highest cholesterol levels on average - 5.7 millimoles per litre of blood.