a very large bird from Africa that cannot fly

The ostrich is the fastest animal on two legs. 鸵鸟是跑得最快的两足动物。

someone who says that a problem does not exist, because they do not want to deal with it

If you're an ostrich about your debts, you're only going to make matters worse. 如果你不愿正视自己的债务问题，只会让事情变得更糟糕。