CLOCKWORK

[noun] [U] - a system of springs and wheels or other machinery which makes some types of clocks, toys and other devices worka clockwork toy/train/mouse(figurative) This office is run with clockwork efficiency (= is well organized).Our bus service has been improved recently and the buses now run like/as regular as clockwork (= at the exact times they should do).The party went like clockwork (= very smoothly and without any trouble).My daughter always calls me on Friday evenings, (as) regular as clockwork (= very regularly).