Consisting of four parts or elements
Rhythm or time having four beats in a bar.
Algebra in which four independent units are used (which may only be added together formally).
A union or association between four powers or states, notably that formed in 1813 between Britain, Russia, Austria, and Prussia in order to defeat Napoleon and to maintain the international order established in Europe at the end of the Napoleonic Wars
= quadruple time; an instance of this.
Four-part counterpoint in which the parts may be interchanged without breaking the rules of counterpoint; an instance of this.
The use of four stages of expansion in a compound steam engine, the same steam expanding successively in four cylinders; usually attributive.
A ratio of four to one.