Longman Dictionary of Contemporary English - clockwork

~ n 1 clockwork toys, trains, soldiers etc have machinery inside them to make them move when you turn a key 2 go like clockwork if something you have arranged goes like clockwork, it happens in exactly the way you planned  (The concert went like clockwork.) 3 (as) regular as clockwork very regular  (Walter came round every Friday, regular as clockwork.) 4 with clockwork precision/accuracy in an extremely exact way