Over-Engineering: n. The art of building something so complicated and unnecessary that it becomes a work of art, but only after 3-5 years of development time.
See also: Under-Engineering, Perfect Design, Technical Debt.
Coined by the ancient Greeks as "O-ver-Engi-neeringus", it was first used by the great Architect, Icarus, who designed a bridge that was so grand, it would have taken 10,000 years to build, but only 3 years to realize it was completely unnecessary.
John's over-engineered design for the toaster that plays 3 different types of music while it toasts, but only after you press 7 different buttons in a specific order, while wearing a pair of socks with exactly 5 different colors.