White elephant- Something that is useless and which is either a nuisance or is expensive to keep up.
In other words a white elephant is an expensive burden; something that costs far too much money to run.
Bob's father-in-law has given him an old Rolls-Royce, but it's a real white elephant. He has no place to park it and can't afford the maintenance on it.
Those antique vases Aunt Mary gave me are white elephants. They're ugly and take ages to clean.
Having spent N85 billion, you said NEPA will still need more money to get to its maximum efficiency.How can you convince Nigerians that NEPA is not a white elephant project?"