clockwork

noun

1. (uncountable, usually)A mechanism powered by a coiled spring and regulated by some form of escapement; the power is transmitted through toothed gearwheels and used to drive a mechanical clock, toy, or other device.

   “Many contrivances for making model horses move up and down as on roundabouts were patented in 1887, and toy horses pulling toy carts were made to imitate galloping by means of clockwork.”

2. (uncountable, usually)The action of behaving mechanically in the manner of a clock.

   “The mind feeds upon the body: pale sickness, and early decrepitude, overmaster even its spiritual essence. Too late it discovers that this earth is its prison, and not its home: the heart beats, and its pulses are the clockwork of wretchedness:...”

adj

1. (attributive, not-comparable)Driven by clockwork.
2. (attributive, not-comparable)Very smooth and regular.

   “In their freight, as in their passenger operations, the N.S. present a picture of clockwork efficiency.”