It had made the family the fundamental unit of the tribe, the clan, the race, the nation.
It is not given to many men to know the ultimate essentials of all horror, concentrated into one fundamental unit.
In just the same way energy can be measured as a quantity in terms of a fundamental unit.
The solar day is the fundamental unit of time, not only in daily life but in astronomical practice.
The fundamental unit of the metric system is the meter (the unit of length).
The metric system is the system of measurement of which the meter is the fundamental unit.
base unit n.
Any of the fundamental units of length, mass, time, electric current, thermodynamic temperature, amount of substance, or luminous intensity in the International System of Units, consisting respectively of the meter, kilogram, second, ampere, kelvin, mole, and candela.