(rail transport) A train consisting of one or more self-propelled cars capable of coupling with other units of the same or similar type and still being controlled from one cab.

(military) A type of military unit armed, equipped and trained to fight in rugged, mountainous terrain.

A unit of form, organization or arrangement of any size.

(In the SI system of units) Any unit derived from one of the seven base units of length (meter), mass (kilogram), time (second), electric current (ampere), thermodynamic temperature (kelvin), amount of substance (mole) and luminous intensity (candela).

Any standardized, reproducible unit that can be used to measure any physical property.

(trains) A locomotive with an engine, generator, and traction motors, but without a control cab.

(linear algebra) An identity matrix

A durational pattern which occupies a period of time equal to a pulse or pulses on an underlying metric level.

(mathematics) the interval [0,1], that is the set of all real numbers x such that zero is less than or equal to x and x is less than or equal to one / (telecommunications) symbol duration time.

(astronomy) 149,597,870,700 metres, the approximate mean distance from the Earth to the Sun (the semi-major axis of Earth's orbit), (symbol AU), used to measure distances in the solar system.