Derived unit of measurement that may be expressed as a product of powers of base units with the proportionality factor one.
Sources:
PAC, 1996, 68, 957. 'Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)' on page 966 (https://doi.org/10.1351/pac199668040957)
VIM (https://www.iso.org/standard/45321.html)