Well we'd have to discuss the item after someone suggests it. Like the steam engine. There's no current applications for it, even in less developed places. Anywhere you can send a steam engine to can also receive a diesel generator/motor. So I would claim that the steam engine is dead, and dead within the last 100 years. But it is certainly not the oldest. https://en.wikipedia.org/wiki/Steam_engine#Present_development, only documented use today (wikipedia) is in R&D. That's dead if the only application is experimenting with bringing it back to life. Typewriters are still in use. Vacuum tubes are very much in use (microwaves and xrays). The vacuum transistor more specifically is also in use. It has higher frequency switching needed for some hi-band microwave-radio applications. So I would say the current winner of the thread is the steam engine. But can someone do better. I promise you there are older things. Also for a date I'm going to go with it's first commercial use, 1698. https://en.wikipedia.org/wiki/Steam_engine#Pumping_engines. It looks like it's not as old as the Ottoman empire though.