Dictionary entry

Cycle (3)

Webster's Dictionary 1913

Cy″cle, n. (a) (Thermodynamics) A series of operations in which heat is imparted to (or taken away from) a working substance which by its expansion gives up a part of its internal energy in the form of mechanical work (or being compressed increases its internal energy) and is again brought back to its original state. (b) (Elec.) A complete positive and negative wave of an alternating current; one period. The number of cycles (per second) is a measure of the frequency of an alternating current.