NCIt definition : A unit of relative amount of substance flow rate equivalent to the rate at which one
thousandth of an equivalent of substance crosses a given surface or is delivered to
a given object or space over a period of time equal to one hour.;
Alternative definition : CDISC: A unit of relative amount of substance flow rate equivalent to the rate at
which one thousandth of an equivalent of substance travels to a given object or space
over a period of time equal to one hour. (NCI);